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Differently tonight on Dateline.

I was a victim of lies and manipulation for far too long. It was hard. It was really hard. I'm not a victim. I'm a survivor.

As we go in the front door, John is lying on a sofa. Gunshot wound to the forehead. He was a firefighter. He had everything in the world going for him.

They took my pride and joy from me. My son gets murdered for what?

The person that called was Jennifer McKay. She had been dating John.

Turns out that she had a previous relationship.

I thought he was divorced. He was not divorced.

Infidelity, married people. This could be a classic ingredient in a homicide.

Correct.

I just said, like, stay away from my husband.

My life has already been flipped upside down.

You got an absolute prime piece of evidence.

It's surveillance footage from next door.

This camera captured the intruder, the killer.

It was just unfathomable.

Jealousy and lies, adultery and obsession. Who shot the firefighter? I'm Lester Holt and this is Dateline. Here's Dennis Murphy with the killer on camera four there.

Amazing grace. The bagpiper's mournful lament for fallen firefighters. It's the way a brotherhood says farewell to one of its own. But this firefighter didn't fall amid the smoke and ashes. His death was deliberate.

He had everything in the world going for him.

I just lost it. My only child and I lost him.

A Baltimore firefighter gone too soon. And the haunting question, who would kill a man so dedicated to saving lives? Thursday, November 30, 2017. Early afternoon.

I would check the well being. When you're ready. 18 eight East Pratt. 18 eight east Pratt. First floor.

A routine request to the Baltimore police for a wellness check.

John Hickley, 31 years of age, has not been heard of since Monday night. His car is not moved either.

A police officer wearing a body cam arrived to find one Jennifer McKay on the scene.

Hey, daughter.

Her boyfriend hadn't shown up for a date the day before and she hadn't heard from him since. She was distressed. This wasn't like him.

And you've obviously posted to be like, hey, are you around?

Yeah. Facebook message him.

I've called, I've texted.

First responders arrived.

The landlord said that he'd open the door. So we'll just see what we see.

They would discover a terrible scene.

Don't touch anything.

Veteran Detective Val Vaughn and her partner, Detective Ryan O'Connor, got there. On the double.

Let's do this. Let's go in and take a look.

I'll follow you.

The boyfriend, John Hickey, had moved to Upper Fells Point recently, the area regarded as safe and quiet.

John's apartment was on the first floor.

What I remember most was it was dark. No lights were on in there.

As we go in the front door, there's a living room area right there. And right there is where John is lying on a sofa. And he is deceased.

John Hickey, 31 years old, a volunteer firefighter, photographer, and Jennifer McKay's new guy, dead on the couch. Obvious injury to him.

Yes. He has a gunshot wound to the forehead, and it looks like John has on t shirts, shorts, and he's lying on his back. There's no other trauma that I could see on John's body.

Could it be a suicide, detective? Before you'd really examined the scene, I.

Didn'T believe it was a suicide, but told you?

No.

The positioning of John's hands, they were folded.

You're not going to roll the body and find a weapon?

Yeah, I didn't think so. And, no, there was no weapon.

No weapon. But it appeared someone may have rifled through his bedroom in the back of the apartment.

When I go back there, it looks like the bed's repositioned. A couple dresser drawers that are drawn open.

Maybe a botch robbery?

It's possible.

On closer inspection, detectives realized John had some pricey equipment that hadn't been touched.

John was into photography. All of his photography equipment was still there.

Good stuff.

Expensive computers, cell phones.

So a puzzling scene in a case that quickly became a little extra for detective Wong.

I'm invested in all of my cases. This one extra because he had no idea. The one thing that came to my mind was, my God, this kid was sleeping.

And a kid, a young guy.

I said, I call him a kid because at the time, he was the same age as my son. So, yeah, I called him. He was a kid.

And now Val Vaughn, Baltimore detective and a mother herself, had to track down another mother and give her the unbearable news.

I remember her just putting her hands up to her face, like, oh, my God. Oh, my God. I don't understand.

When she told me that he was murdered, I couldn't believe it.

Kim Hickey, john's mom.

I said, I just talked to him not too long ago. And she said, well, he's found and shot, and I just lost everything. I mean, they took my pride and joy from me.

I got a phone call, and I think it was from you.

John Hickey is Kim's brother and a volunteer firefighter himself. His nephew, young John, was named for him. Mother and uncle went to John's apartment, still in shock, in grief, and utterly baffled. He's a firefighter. You accept danger with every shift. And then to be shot to death in your own home.

Exactly. It didn't make sense.

A death so sudden and brutal, no one could make sense of it.

Somebody's got a beef with him. But who would it be?

Finding that out would take John Hickey's family down a dark path, revealing long held secrets.

They were calling and texting John first, saying, like, this girl's bad news. You need to look out for her. She'll ruin your life.

A stunning piece of evidence. That's going to be a huge light bulb moment. Look what we have here.

It was. It was one of those moments where.

You say, wow, and a wife confronted with a devastating accusation.

I mean, what do you want me to say?

Absolutely nothing.

There's no secret.

We need to get in touch with family.

When first responders arrived at John Hickey's Baltimore apartment for a wellness check, they met Jennifer McKay, John's new girlfriend. She was worried sick.

I Facebook message him. I've called, I've texted.

She and John had been on a date earlier in the week. Here they are on CCTV. Then John went silent. She waited while responders went into the apartment.

Ma'am, we're going to have the medics come.

And she got the devastating news right there on the spot.

In order to resolve this situation, hopefully, we're going to need your help. We're going to need you to stick around, okay?

Hours later, Jennifer sat down with detectives in this interview room. How does it go down?

I think Jen was in shock to.

Be here at that state of the investigation. Detective, what specific questions did you have for her?

Basically a sequence of events, a timeline.

The timeline began some six weeks before when Jennifer McKay and John Hickey met online and then in person went to.

Watch a hockey game.

Y'all hit it off after that.

Kind of seen each other almost every day since then.

Who is she turning out to be?

Turns out that she was trying to start a new life with John. She appeared to be happy. Just a regular boyfriend girlfriend situation.

In the little time that you all.

Were together, the relationship was pretty good.

Tuesday night, he left a cute little note in my purse for me to find the next day, which was hard to take because at the same time of not knowing where he was and.

Reading it, was there an understanding that.

You all were exclusive?

Yes. There is nobody else, and he is what I wanted.

John seemed to feel the same way. Vaughn and O'Connor learned that he spent Thanksgiving with Jennifer and gushed about her to his mom, Kim Hickey. You met her. What did you think of her?

I thought she was pretty nice. We got along great.

Do you think this was a serious woman in his life?

He said, mom, she loves everything I'm doing. She's into the hockey and all this stuff that I do and everything. And I thought, okay, well, it's too soon, but I'll just keep an eye and hope everything works the right way for you.

His firefighter buddies heard about her, too, and they gave him a little good natured grief about love in bloom. Brian McDermott, John's mentor. Scott Amy, a volunteer who rode with John and uncle John Hickey. He was smitten, huh?

No, he was alone. He wasn't smitten. We talked about that, too. When he posted. He changed his status to in a relationship on Facebook. And then Jen made the joke. Yeah, he told everybody else before he told me, but you could just see he had butterflies. You just could see it. He was in love.

Things were coming together for John in his professional life, too. He came from generations of firefighters, began volunteering when he was 21. His home station was here, the Woodlawn volunteer fire company, station 33. Did he have it? Was he going to make it?

Well, you don't know that till he hits that fire. But when you hit that door, that's when you know if you have a firefighter for you or not.

How did he do?

He went through the door. He went through the door and I'll say 90% of firefighters probably can't make it through that door.

The detectives learned John was about to become a full time firefighter for the Baltimore City fire Department, due to enter the fire academy a few days after he was killed.

He was so excited. He called me. He said, mom, he says, I told you everything is falling into place. He says, I got my house. I just got accepted to the city fire department. Everything is coming together, and I found the person I love.

Now John's new love, Jennifer McKay, was sitting in a police interview room, and she was about to shed some light on his mysterious death. In the weeks before John was killed, she said strange things started happening.

We have been getting harassing phone calls.

And what did they say?

So the first round was to John about me.

So they was calling John.

They were calling and texting John first, saying, like, this girl's bad news. You need to look out for her. She'll ruin your life.

Okay.

I don't know who's doing it. The numbers are spoofed.

Then, a week before John was killed, his dog, a border collie named Chance, suddenly died.

Well, the dog was. That was his world. Just a beautiful dog. He came in that day. He was in tears and. Yeah, when the dog were, too, yeah.

He came home and found the dog dead.

The dog started getting sick. All of a sudden, the dog was in perfect health, and we assume he was poisoned.

There was never any proof of that. But then something happened that was potentially deadly. The brakes in John's car were tampered with.

It was cut, which would eliminate your brakes completely. Once the fluid ran out.

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Book now on irishferries.com and see travel differently. Hey, guys, Willie Geist here, reminding you to check out the Sunday sit down podcast. On this week's episode, I get together with Academy Award winner Kate Winslet to talk about playing a dictator losing her grip in the buzzy new miniseries the regime and reflections on that disorienting whirlwind of Titanic. You can get our conversation now for free wherever you download your podcasts. John Hickey's family was reeling over his murder. As far as they knew, he didn't have an enemy in the world.

I didn't know anybody that was really angry with him. That's why I couldn't figure out how come my son gets murdered for what he was.

Just that person that he was always giving, always giving, no matter what it was.

But it seemed someone had targeted the young firefighter. In the weeks before he died, John was getting harassing calls. The dog he adored died suddenly. And then the most chilling thing of all, at the end of a weekend at his girlfriend's home an hour north of Baltimore.

And when John went to leave Monday morning, there was something weird going on with his vehicle. Like his brakes weren't working correctly.

Since John knows cars, he immediately, when he started his car, put the foot on the brake and knew there was no pressure and knew there was a problem.

John Hickey knew his way around a car. He made his living as a mechanic.

John's mechanically inclined.

And his buddy Scott Amy owns an auto body shop. When John showed Scott what had happened, Scott was sure someone had deliberately tampered with the rubber brake line.

No doubt in my mind that this was a cut brake line. Whether it was a pair of scissors or a knife. It was cut, which would eliminate your brakes completely once the fluid ran out.

Which meant if he tried to drive the vehicle, it would have ended in wreck.

Correct.

What does that tell you? Something's going on with this guy.

It appears that someone is out for Mr. Hickey.

Did you think there was a straight line to him being a victim dead on his couch of a gunshot?

It seemed like a series of events were starting to add up to what ultimately ended up being his death.

But how to find whoever was behind those events? Were they even connected to John's murder? They couldn't rule that out. In the police interview room, the detectives probed Jennifer McKay looking for leads.

I appreciate you coming down here and speaking with us. We still early in the investigation? Just trying to figure out who would.

Want to hurt John.

There's too much weird stuff going on, and I don't know what's going on. I don't know how it's connected.

It would be up to Vaughn and O'Connor to connect the dots. They were wondering exactly how John's new girlfriend fit into the picture. You don't suspect her or you can't go that far at this point.

At that point, I don't suspect. I don't. We had nothing know tied her to the death of John Hickey. But keep in mind also that when we're speaking with her at that moment, remember the case is unwinding, like we're gathering information as we're going along.

The detectives continued to gather information from the crime scene as well, focusing on how the killer may have entered John's apartment.

There is a rear door opened.

First responders found the front door locked and bolted. So it looked as though the killer got in from the back of the apartment, accessed by this narrow passage. Detective, you really got to scope these buildings out to figure out what's back here and how you find where you're going.

Yes, you do. Definitely do. And have to watch your steps.

The passage leads here. So where are we now?

We're behind John's house. This is his apartment.

When detectives surveilled the back alley, they saw this.

And lo and behold, there's a camera looking dead at us. Picture perfect.

The camera was mounted on a neighbor's house pointed at John's back door. Is that where you'd want to place a camera for what you're looking for?

Absolutely. I couldn't ask for anything better than that.

Right there for this case, it was perfect.

Picture perfect. Picture perfect.

A TV director himself would have put.

It in that same place right there.

But accessing the camera wasn't going to be simple. This is a citizen's camera. It's his property. Presumably, it's not a city.

Yes. So we have to make efforts to contact the owner of the camera and get permission to get the camera itself so we can pull in the footage and review it.

The million dollar question, was it even running on the night of the murder?

Sometimes we get lucky.

And this was one of those times. The camera was running that night. With fingers crossed. The detectives sent it off to the crime lab to download the footage, and they turned their attention back to the scene. And another promising lead. Something lying in plain sight. A document belonging to a stranger. So, in the front room, we've got a man shot through the forehead.

Correct.

And in the back room, we've got a passport.

Correct. Who is this person?

Is this your killer? Who may have inadvertently left this ID behind?

It's a suspicious death. It appears to be a gunshot wound to the head.

Baltimore police were investigating the death of a volunteer firefighter, John Hickey, discovered dead on his couch. No signs of a struggle. John's station house buddies were still trying to wrap their brains around it. I mean, all of you know, you may not come back from a given shift if something goes wrong, but that's not what this thing was.

No. And we could accept it if it. Different story. If he died in a fire, we'd still be terrible, terrible thing to do.

But guy's sleeping on his couch and gets a bullet between the eyes.

You can't get much more innocent sleeping. I mean, it's just devastating. It was horrible.

It was a scene that haunted even a seasoned detective like Ryan O'Connor.

Something I always remember is his slippers were, like, perfectly lined up right in front of the couch where he was laying. It was literally like he took his slippers off, and then it was going to lay down, watch TV.

He had everything in the world going for him. Everything. He was nice looking. He was young. He was energetic. He had the world at his fingertip.

The detectives were working several intriguing leads, but so far, they hadn't caught any big breaks.

We didn't have a witness. The witness is the most key thing that you could possibly have in an investigation. It was basically, unfortunately, a dead person inside of a house and no witness to tell us the story behind it.

You wish the neighbors heard something they didn't?

Yes.

Do you wish the crime scene text had come up with something they didn't?

Fingerprints, DNA, something that says, we're in the right ballpark.

Cancel your vacation.

It's going to be a long one.

They knew one thing. The scene in John's bedroom looked fake, as if someone wanted it to look like a robbery. But nothing was taken.

It looks like it was tossed, but it looks staged.

Someone wants me, the detective, to think that this was a burglary.

It looks staged.

John's photography equipment wasn't even touched, and it was high end gear. John was a passionate photographer, earning money from his pictures, posting videos of himself on YouTube, prowling around, camera in hand. One time, he finagled his way into this old building down by Baltimore's docks.

Somehow, he sweet talks the guard to get through the gate, and he's in this abandoned building, and he gets his picture of this amazing life that has to be a hundred years old or something.

It was a hobby that sometimes took him into dark corners of the city.

He loved the city. He would go all over the place in the city? Yeah, all hours of the night. He'd go into places where you and I not necessarily would want to be, but he had no fear.

Did a nighttime encounter in one of those abandoned buildings come back to haunt him? Or was it someone closer to home? The detectives had discovered something at the crime scene. A clue, perhaps, almost staring them in the face. A passport belonging to a man no one seemed to know. A guy named Brandon. So in the front room, we've got a man shot through the forehead.

Correct.

And in the back room, we've got a passport. Are these things related? That's what you're wondering? I guess, as a detective?

Correct. Who is this person?

Is this your killer who may have inadvertently left this ID behind? So that was the frenzy of fleeing the place, somehow lost his passport.

Yeah. So that was definitely part of the investigation that we had to track down and run out that lead.

And that's what they did, track down Brandon and interviewed him.

You have a passport. Do you know what happened to your passport?

Brandon told them he couldn't remember because he'd been in a coma following a nasty motorcycle accident the year before.

Literally, it broke every single bone in my body, all my ribs, both my legs, my pelvis shattered, both my arms, my neck. Brain injury. So I literally died on the scene three times.

He had a traumatic brain injury, and he said there were a lot of things he didn't recall. He did not know who John Hickey was, and he believes that he lost his passport at some point. Not sure where, how or when how.

Brandon's passport got into the apartment remained a mystery. When detectives asked Jennifer McKay about it, she said she'd never heard of him.

Do you know anyone named Brandon?

No. I mean, I know people named, like, associated with John? No, not at all.

But there was someone else Jennifer mentioned to detectives that caught their attention. She said she called a man right before she asked for that wellness check on John.

You talked to him today?

I did talk to him.

What time?

I've been talking to him since all this has been going on.

It was weird. It was OD at best. I didn't understand it.

One week after John Hickey's murder, friends and family gathered to bid him a final goodbye.

It was a huge procession for his funeral, flying flags. We had bagpipes. We had sea of blue. Firefighters go before us and create what we have today. They better us by what they've done in the past, but John bettered us by what he did. May he rest now forever in God's peace. Amen.

Hey, John. You never got him out of the fire academy.

Yep. It's tough. Yeah. He was the one to carry it on. I didn't have a son to carry it on with, and he was kind of like a son to me. Yeah. I miss him.

Detectives believed whoever killed John Hickey might somehow be connected to his new girlfriend, Jennifer McKay. After all, Jennifer was the subject of those harassing phone calls John had received. And John's brakes were tampered with while he was staying at her house. So detectives took a closer look at something Jennifer said during her interview. Something about a call she made moments before asking police to check on John.

Name?

Yes.

Daniel Green.

The call was to a Daniel Green. She told detectives she called him for advice on how to request that wellness check. So who was Daniel Green?

How long have you known Daniel?

My entire life. Literally since I was four years old. He was friends with my brother in elementary school, and we grew up together.

How did she describe her relationship with this guy, Daniel Green?

She basically said that they were friends.

Detectives dug into Jennifer McKay and Daniel Green's relationship and went back in time, years before the murder. Daniel was a firefighter, part of the brotherhood, just like John. But Daniel served for a company in the suburbs about an hour outside Baltimore. You do a little background check on him? You coming up with anything? What do the computers tell you?

He has no criminal arrest record. He seems to be, by all accounts, a loyal son. The great father.

And detectives learned Daniel was married to another Jennifer. She goes by Jen. The two met in a bar back in 2006. And how was this guy you just met him.

He was nice, charismatic, funny. We had similar interests. We were both raised in the church, so that just kind of drew me to him.

Jen, a stay at home mom and freelance travel agent, liked that. Daniel was a well respected firefighter.

He was very proud to be a firefighter. He seemed to love it.

Good day. You saved somebody's life.

Yeah, for sure.

Most important of all, Daniel doted on Jen's daughter Kayla, from a previous marriage. Did she like him?

She did. She liked him a lot. They were very close.

So close that when Jen and Daniel decided to tie the knot, he made sure Kayla took center stage at their wedding.

After we did our vows, he read something to kayla and gave her a ring and was, like, promising to take care of her and be there for her. So it was like a whole words.

That you were happy to hear.

Yeah, very much so.

Daniel and Jen went on to have a child of their own, baby, Madeline Grace.

He was a very dedicated and devoted dad, very present for both kids.

So you thought you made a good choice as a good guy?

I did.

I really did.

But things began to change in 2009 when Daniel suffered a serious injury on the job. While fighting a fire, he inhaled hazardous gasses that damaged his lungs.

And then he started with, like, a really bad cough, difficulty breathing. Anytime he got a cold or anything like that, it was full blown respiratory issues.

In June of 2013, Daniel was medically retired from the job. How did he deal with that? I mean, he's hanging up this career that he's so invested in terribly.

You could see that he just didn't really know how to deal with the loss of this career. He was not the same person after that.

The job loss took a toll on their marriage as well.

The tides were turning with us, and there's tension in our marriage and what are you going to do? How are we going to pay our bills?

Jen said Daniel slowly grew more distant.

I noticed that he wasn't really accepting advances for me anymore. And as a woman, you kind of are. Like, there aren't many men that are going to turn it down. That's just how men are. So I kind of put two and two together. Know he has to be getting this from somewhere else.

Then four months after Daniel retired, Jen discovered gut wrenching proof Daniel was having an affair. How'd you know that? He was messing around.

It was all over our phone bill. Thousands of text messages to his mistress.

Did you know who she was?

I did. I called the number and she picked up and I knew her voice.

Turns out the two women ran in the same social circles. And she knew you?

She knew who I was. She knew who his wife was. She knew who his kids were. She knew who his family was, for sure.

Who is this person? Who is the other woman?

Jen McKay is her name.

Jennifer McKay, Daniel's longtime friend. The same woman who would later start dating John Hickey and who'd call police, asking them to check on him. During their investigation, detectives learned about the affair, too, from Jennifer McKay herself.

How long were you guys together, you.

And Daniel, like, officially? Two years. There's about another two or three years. Where it was, I'll be honest, it was a straight affair.

Did she know, detective, that he was a married guy?

Yes.

But what did all of this have to do with John Hickey's murder? Detectives were determined to find out. After all, affairs of the heart can be messy, and Cupid's arrow can be deadly.

I mean, the common denominator is Miss McKay. She seems to be the linchpin for whatever occurred.

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For true crime fans, nothing is more chilling than watching Dateline. Have you ever seen such a thing before? For podcast fans, nothing is more chilling than listening what goes through your mind.

When you make a discovery like that.

And when you subscribe to Dateline premium, it gets even better. Excuse me if I sound a little skeptical. Every episode is ad free.

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You ready for what's coming?

Firefighters subscribe to the adage, where there's smoke, there's fire. Homicide detectives have one, too. Where there's murder, there's often infidelity. I'm thinking this could be a classic ingredient in homicide.

Correct?

Infidelity, married people, domestic related. Do you do that same kind of math?

Yes.

Detectives Vaughn and O'Connor learned that four years before Jennifer McKay started dating John Hickey, she began having an affair with the very married Daniel Green. Jen, how hurtful was this infidelity?

Oh, it was.

Put some words to it.

It was horrible. It was just, you wonder, where did I go wrong? I finally confronted him and said, hey, what's going on here? And he's like, we're just friends. I'm like, I have a lot of friends, and we don't text message thousands, like 1500 a month text messages between them. I was like, look, we can go to counseling. We can talk about what's going on. And he was like, no, there's nothing wrong. I'm going to stop talking to her. I've stopped talking to her.

It's all over. It's done.

And it's not on my phone, know, on our phone bill. So I'm like, okay, helping matters.

Daniel, by now, had landed a great new job teaching military personnel how to use firefighting equipment.

And that required travel to different army bases.

Seemed to be a good fit for his totally. But the smoldering embers of an illicit affair can be hard to extinguish. Jen began to sense Daniel drifting away again. His work trips were getting longer and longer while family vacations were getting shorter and shorter.

I specifically remember one we took Madeline. We surprised her with a trip to Disney World. And at the end of the trip, he said, I have to leave. He's like, I need you to drive me to the airport in Tampa. And we were in Orlando, and I'm like, why do you need to fly out of Tampa?

He was running out on, yeah, just.

Like, leaving a sign dry. And I flew back home with my daughter alone.

People probably wonder at this point why you didn't give his marching orders. Hello, 1800 divorce, you're done.

I grew up in a christian home where you fight for your marriage, you figure out, hey, what's going on here?

Then came November 2016, one year before John Hickey's murder. The weekend after Thanksgiving, Daniel told Jen he was taking their daughter Maddie to a buddy's house to watch football.

They came home at, like, seven or 08:00 that evening, and in line with when a football game would end, while.

Putting Maddie to bed, Jen asked her if she'd had fun watching the game. That's when Maddie unwittingly dropped a bombshell.

And she said, we didn't go there. And I said, what do you mean? And she said, oh, we went to daddy's friend's. Jen's house for Thanksgiving with her family.

With her family.

With her family and your daughter together?

Yeah.

And I was, uh. I'm sorry, what did you just say?

Is this a big moment from the.

A huge, huge moment for me?

Jen had hit her breaking point. After putting Maddie to bed, she stormed downstairs to find Daniel.

I just said to, you know, were you at Jen's house tonight? And he was like, no, you're crazy. Why would you say that? And I said, well, Maddie just told me you were there for Thanksgiving with her family. And he's like, why would you listen to a little kid? She's lying.

That's when Jen grabbed her car keys and drove off to confront Jennifer McKay. If her husband wouldn't tell her the truth, maybe her husband's girlfriend would.

He was calling me nonstop, calling me, texting me, telling me to come know, I better not go to her house. I better stay away from her. I knocked on her door. She answers the door, and, you know, was my daughter here today? And she said, yeah, it was Dan's weekend. And I said, I'm sorry, what? And she said, it was his custody weekend.

It took Jen a moment to absorb the word custody, as in child custody after a divorce.

And I said, I think we need to talk. We're still married. And her face just kind of went blank. Like, what? And she just said, come inside.

So, sister, we got to talk.

Yeah.

It didn't take long for the two Jens to reach the same conclusion. Dan had been lying to both of them.

She tells me, I thought that you guys were divorced. And I thought you had joint custody.

Daniel, she said, even had proof.

He had shown her fake divorce papers and she pulled them out.

Fake divorce papers?

Yeah.

During Jennifer McKay's police interview, she told detectives about Daniel's deception.

I thought he was divorced, okay? He was not divorced, okay? I thought he then separated. So we were trying to work things out.

He's leading her to believe he left his wife for her. They're going to build out their own happily ever after.

The two Jens spoke for 15 headspinning minutes. Then Jen Green left Jennifer McKay with these parting words.

It just kind of went, stay away from my husband and my family. And I walked out of her house and came home.

As Jen pulled into her driveway, she expected to find her husband primed with apologies, waiting for her at the door. She was wrong.

He didn't even talk to me. He just left.

Daniel, she said, headed straight to Jennifer McKay.

He wasn't even interested in making it okay with me. He was more concerned with going to her and making it right with her.

Extra hurt him.

Yeah. I mean, in that moment, my whole world collapsed. I didn't think that he was that enamored with her that he was willing to put everything on the line that we had to be with this woman.

Now, detectives Vaughn and O'Connor were wondering, was Daniel so obsessed with Jennifer McKay that he killed her new boyfriend? Before they could follow that lead, the detectives got a break the footage from that security camera came back from the lab. That's going to be a huge light bulb moment. Look what we have here.

It was. It was one of those moments where.

You say, wow, a big break. Indeed. And one that would put Jen Green in the hot seat.

There's no secret here that my husband is up when it comes to being a good husband.

Detectives investigating the death of John Hickey had to make sense of several messy and intertwining love affairs. At the center was Jennifer McKay. Her romance with Dan Green had brought his wife Jen, to a breaking point. She told her husband that if he wanted to leave the house, fine, but she was staying. It sounds like you've come to an arrangement.

My stance was always, if you're unhappy, you can leave. This is where our children live. This is know. If you're unhappy, you can leave. There's the door.

Dan said he would stay, though he left the house often for days to be with Jennifer McKay. When he was home, he slept on the couch in the basement. So this is his hangout when he's in the.

Huh? Yeah.

If he's here, he's downstairs. He's never upstairs.

Soon, there would be no place for Dan. With Jennifer McKay too frustrated by his apparent refusal to commit to her, she called it quits in August 2017, three months before John's murder.

She was tired of being second fiddle. She was tired of being the other woman. So after a while, she said she couldn't live like that.

So she moved on, moved on to John Hickey. But detectives learned that despite the new relationship, Jennifer McKay and Dan Green continued to call and text each other. Here's what gets me. She starts talking to Green about the new guy in her life, her new boyfriend.

She was. It was perplexing to hear because I could not understand why are you still conversating with this guy if you're done with him and especially telling him about the new man in your life? Did you actually talk to him about the relationship with John?

Only that I was dating him and seeing him.

Any reason in particular why?

So hopefully, he would have closure and accept that I'm moving on with my life.

Okay.

I made it clear because I wanted him to leave me alone, which he hasn't done.

So he has not left you alone?

No.

But McKay made one thing clear. Whether Dan let go of her or not, he'd never resort to violence, let alone murder.

I mean, I don't see him doing anything stupid in this sense, because he has kids. A kid and a stepdaughter. I don't see him jeopardizing that relationship. I don't think he would go to that extreme.

As detectives unraveled all of the complicated relationships, they got word from their crime lab. It turns out there were several surveillance cameras rolling the night John died, and technicians had downloaded the footage. It was this camera, camera number four, that provided the breakthrough detectives had been hoping for. A man emerging from the shadows, pacing back and forth behind John's apartment, pacing.

Between the t in the alleyway right there, up here, checking windows. Basically getting up the courage to actually.

Know, am I really going to do this? That's what you see, the thought balloon in his head? Yes. He seems to be trying out one window after another.

He does. He goes in between. He goes in between this window. He's trying that one. He tries this window right here. And ultimately he's successful that he's able to hoist this window up and get.

His body just gets himself up and pulls.

He goes completely inside the window. Yes. And he disappears.

And he's about to kill the guy. And you can't stop him.

Yes.

So once the intruder makes his way inside of this window, there's some time that passes and you see someone leave out of this door who we believe is an entry.

You see the figure?

Yes. He comes out of this door. And what you can also make out is that in his hand. It appears to be a handgun.

Wow. How important was that as evidence for you?

It was crucial. It was literally the biggest piece of the puzzle.

At one point, the man's face comes into full view. Here's my close up.

Yeah, it's my face.

Did you think, how can a perpetrator be so stupid?

No, I just thought, how could we get so lucky?

The alley is dark. The figure hidden by an oversized jacket, the hat pulled down low. But detective Vaughn had seen Dan's driver's license photo. And the minute she saw the video, she felt sure.

The first thing I say is, oh, my God, that looks like him. Oh, my God, that looks like Daniel Green. It was shocking. Shocking that there's a guy on this video that looks just like the boyfriend of our victim's girlfriend.

But in order to make their case, they needed an identification from someone who really knew Dan. And few knew Dan better than Jennifer McKay.

I think you were aware that we were looking at the cameras from the house next door.

They brought her to the station again and showed her the surveillance video and some close up photos of the intruder.

Does it look like.

It looks like Dan?

Why does it look like Dan, the beard. Anything else?

The build. Okay, but, I mean, it's hard to tell face wise if it's him, but it looks like his stature.

Fair to say. The person in your chair is having the worst days of her life.

She is.

That's what I see, too, when I'm sitting across from her and I'm asking her to sit there and tell me if this is the Daniel Green, if this is a man that you once loved. Because we're saying that we believe that he killed your new boyfriend, John Hickey.

You can see it? Yeah.

What time is that on there?

126.

Okay.

It looks like Dave.

From these pictures.

Yes.

I would say this looks like him. Yes.

Nobody's telling you to say one way or the other. We just need to know.

No, it looks like him.

How close do you get to a positive ID of those photos as being.

Daniel Green when she says, this is Dan, we have a positive ID.

Your past maybe should have.

Yeah, we're well know the woulda, coulda, should haves. We are positive this is Dan.

It was a game changer. Investigators believe they now had enough to arrest Dan Green for the murder of John Hickey. Turns out Dan Green would have a lot to say about that.

I think you don't have much to work with, and you're throwing things at the wall at this point.

Sail from Dublin to Sherborg and start a wine tasting before you even get to France.

That's bonjourneying.

Book now on irishferries.com and see travel differently. Hey, guys. Willie Geist here, reminding you to check out the Sunday sit down podcast. On this week's episode, I get together with Academy Award winner Kate winslet to talk about playing a dictator losing her grip in the buzzy new mini series, the regime and reflections on that disorienting whirlwind of Titanic. You can get our conversation now for free wherever you download your podcasts. So, Jen McKay has advanced your case. You showed her pictures, and she said, that's him. That's my ex boyfriend. That is Daniel Green. What's next on your to do list?

Arrest Daniel Green.

Dan was arrested on December 5, 2017, a week after John was murdered. 35 year old Daniel Green, a married.

Father of two with no criminal record.

Faces eleven counts against him, including first degree murder. John's firefighter friends found it hard to believe that John had been unwittingly entangled in a love triangle. Even more shocking, his alleged murderer was one of their own. This isn't a street criminal coming in to grab stuff. It's a fellow firefighter. It's one of the brothers.

Yeah, that's the first thought. No, a firefighter couldn't do such an act. That's what I thought.

Right?

I mean, some of us could be screw ups, right? To kill somebody, let alone another firefighter in your family or brotherhood.

How? John's girlfriend, Jennifer McKay, had attended John's funeral, but she kept her distance, consumed by guilt that her former boyfriend might have been responsible for John's murder. But when Kim saw her in the back, she graciously invited her to sit with the family.

She did not feel that she wanted to come near me because she thought I was angry with her for all this happening to my son.

Were you?

And I was not angry with her at all. I said, I'm not angry with you because you did not put the gun in the guy's hand. You did not tell him to go shoot my son.

Police came to the same conclusion. Jennifer McKay had nothing to do with John's murder, but they believe they had plenty of evidence to put away her former boyfriend for the crime. First, that back alley video they said showed Dan Green climbing into John's apartment. But also, Dan was arrested while driving a black pickup truck. And detectives believe it was the same truck they spotted on surveillance video near John's apartment on the night of the murder.

So we found a camera next block up that shows black pickup truck driving, parking, and the suspect getting out and going down towards John's house. And then same black pickup truck, suspect goes to, drives off. And the time it matched up between showing up in the alley to the person darting out the back door, we.

Couldn'T tell who was driving the vehicle based on the footage, and we couldn't get a tag number, but it appears to be the same truck that he was arrested in.

There was other compelling circumstantial evidence. On the night of the murder, Dan shut off his phone at 08:25 p.m. Then turned it back on the next morning at 09:20 a.m. For a man who lived on his phone, that was strange, to say the least. Is it out of character for him to not have his phone with him?

It would be probably out of character, yes.

Even stranger, the last place Dan's cell phone pinged hours before the murder was a vacant house, nowhere near his home or work. What was he doing there? Detectives got their answer when the homeowner went to check on his property.

And when he gets there, he discovers that someone has been living in his property without his permission. They set up house. They had food in the fridge. They had clothes in the dressers. They had dishes.

They even had a cat and mail addressed to Daniel Green.

There were pictures and letters from Jen McKay there. There was also a Prince George's county firefighters uniform hanging up in the bedroom closet.

Detectives believe Dan Green squatted in the house off and on after Jennifer McKay broke up with him. They said it was all part of his ruse to convince her he'd left his wife for good and to rekindle their relationship. What does it tell you about him? What did you make of that?

He's living a double life. He's going to extreme measures to live his lies.

Dan was willing to break the law to keep his girlfriend. What was he willing to do if he was about to lose her to John Hickey? For detectives, the answer seemed obvious. Murder.

I just want to understand why you killed John Hickey.

I didn't kill John Hickey. So that's a moot point.

During his police interview, Dan freely admitted that he had an affair with Jennifer McKay.

Tell me about you and Jen's relationship.

It was very good and very passionate, and I couldn't move on and fully commit to her.

I asked him, did you know about the boyfriend? How did you feel about the boyfriend? And he says, I wish her well. I wanted her to move on. Do you believe that? If Jen came back, would you take her back at this point in your marriage, in your life?

Probably not, no.

He also told me, he says, well, I really wasn't in love with her. Do you still love her?

No, I really don't.

You can't just stop loving her. It's like saying, I stopped breathing over the weekend. That doesn't even make sense.

There are different types of love. This is not a white hot I will drop my world and come running to you, but there will be feelings, and there is a feeling for her that will be there, and it'll always be there, but it's not that. What do you need? Whatever. You want me to ditch my life, ditch my family, and I'm. No, that's gone.

That, Detective von thought, was a lie. Jennifer McKay had shown her post breakup emails and text messages in which Dan seemed obsessed with her. Police theorized it was unrequited love, and it drove Dan Green to shoot John Hickey while he slept.

You thought nobody saw you, wasn't there, so they couldn't have seen me.

Okay, all right, so you thought nobody saw you, when in fact, everybody saw you. In case you haven't figured out in 2017, guess what? Everybody has video, okay? Everybody has video. Just so you know, you're on video.

But Dan Green kept insisting that wasn't him climbing into John's apartment. Andy claimed he could prove it.

It sounds like you've made your mind.

Up, but no, the facts have made their mind up, sir. The facts? It's called evidence.

You have pieces of evidence. You don't have the full evidence. It appears. I think you don't have much to work with, and you're throwing things at the wall.

At this point, I don't care what you got.

Yeah, you got the wrong guy. I have an alibi. It wasn't me.

Dan's alibi. It was so surprising and unexpected, police didn't see it coming. And when Dan's wife, Jennifer Green, walked through the doors of the police station, detectives realized they had a problem.

When your husband cheats on you as long as mine did, you know when he comes to bed at night and when he doesn't?

Detectives told Dan Green that his obsession with Jennifer McKay gave him every reason to kill John Hickey.

Someone else is making her smile. Someone else is making her day. And it's not you.

In your theory, why is Daniel Green's life better improved by killing John Hickey?

If he couldn't have Jen, then no one could.

At the police station, Dan insisted that he didn't have any lingering feelings for his former lover. And in fact, about a week before John's death, he had a revelation.

Watching my wife struggle through and never giving up. And it might not be perfect, but it's rare to find someone that is that devoted. And that is probably something I need to take into account a lot more.

So he started making an effort, showing up, trying to be the husband Jen wanted him to be. The night John was killed, Dan told investigators he was in bed with his wife, Jen.

I think Tuesday and Wednesday, I slept with my wife in bed. At any point, did you leave the house? No, sir.

Given the state of Dan's marriage, it was a curious alibi, to say the least. But it made total sense to Dan's parents, Beth and Randy Green, who were squarely on their son's side.

It takes a while for it to sink in, and even then, you don't get it.

Beth and Randy were horrified at his arrest. They're Daniel, behind bars and accused of murder. It was incomprehensible.

If you were in a fire, he'd be the very first guy in the house trying to get you out of the house. But that's the kind of person he is. When that man gets shot in the head like that, that shows a lot of hate. That's a lot of anger.

Build up, execution style.

Yeah. Why would you go into somebody's house and do that? Our son would never do that.

Beth and Randy were determined to prove their son's innocence, so they began methodically picking apart the case against him, starting with that video from the alley.

There's a guy walking. And we said, daniel doesn't walk like that. The guy looks bigger, he looks wider. The clothing's different.

We knew it wasn't Daniel, but we wanted to be able to prove that beyond a shadow of a doubt.

Toward the end of the video, they thought they'd found what they were looking for. A moment where, for a split second, the intruder turned his face to the surveillance camera. Why is this not a picture of your son?

There's a break right at the nose. Right up here. Initial right at the bridge of the nose. There's another break right there. So this man had his nose broken at least two times. In my opinion.

Most likely, something's going on with the nose.

There's a bald spot on the chin right there. Daniel has a full beard. There's also a bald spot on the mustache right there. There is some bruising on the side of the face. That's right through there. It's not him.

Randy Green had a forensic lab enhance the photo and then sent it to police and the state attorney's office, hoping they would reconsider their case against Daniel.

They never did.

They never did.

So why didn't know? Because they do not pursue evidence that might clear somebody.

It's a situation where they zeroed in on one person. They said, this is who it's going to be. Now, let's come up with a story that fits that narrative.

Tom Moronik Jr. Is a defense lawyer who worked on Dan's case and took a close look at the evidence against him. Tom, I think I hear you saying that this is a rush to judgment.

That's exactly what it is, Dennis. It's a rush to judgment.

And there are no forensics, which juries love, to button it up and make the decision for them.

Forensics can rule someone out. Forensics can indicate a high likelihood that it's the person they're accusing. But they didn't do any of that here.

That's right, said Dan's trial lawyer, Warren Brown, who charged. The investigation was a mess from the get go. He pointed to a palm print on a windowsill in the back alley that he says police never analyzed.

They didn't check to see the size of it, whether it was his size.

What about the man whose passport police found inside John's apartment? Yes. Detectives tracked him down and interviewed him, but Brown said they didn't scrutinize him enough.

He told them he had been in an accident. He didn't have much of a memory about back then, and he's not sure how his passport ended up in this deceased home. They said, okay, all right, have a good day. We just had to check you off. But that was it. I mean, they took his word for it.

Then there's the issue of the black pickup truck. Police believe Dan drove to John's apartment on the night of the murder. Like I said, dan didn't own a black pickup truck, but he sometimes borrowed one from his neighbor, Jim Robo, back in 2017.

I had a black Ford ranger, and I always parked it the same place I parked my truck now, the red ram down at the garage there.

Robo said that police never questioned him about the truck. And if they had, he would have told him there was no way Dan took the truck the night John died.

And this is where I hang our keys for our vehicles. If Dan would have came in that night. We have a Jack Russell terrier here in the house, and he's our watchdog, and he barks. He goes crazy whenever anybody comes in the house. And we didn't hear peep out of him that night. So I'm sure Daniel didn't come in to get the keys.

And as to Dan's alleged motive for.

Shooting John, the boyfriend is jealous and know his girlfriend's new boat.

But Brown said that during her affair with Dan, Jennifer McKay had several relationships with other men that Dan knew about.

So why does this now become a motive to kill this guy? All I gotta do is outweigh him. I gotta go kill him.

Murder, said Brown, was the last thing on Daniel Green's mind as he headed to bed that November night, the night he said he spent with his wife, Jen.

Well, I think that I was at home with my wife. Who will account that I was home with her?

Would she? After four years of enduring her husband's cheating, betrayal, and lies, what would Jen Green have to say?

If you could just start from the beginning and tell me what you remember about that night in particular.

I got home at 11:00 came in. Dan was downstairs on the couch watching TV. And I went upstairs, checked on the kids. Both kids were asleep and got ready for bed. And maybe, like, midnight, Dan came upstairs.

Got in bed, there it was, clear and unequivocal. Dan's alibi that night in particular.

Why is that so vivid to you that night? How do you remember that when your.

Husband cheats on you as long as mine did? You know when he comes to bed at night and when he doesn't?

Okay.

And I know he came upstairs and got in bed with me that night. And those things might seem mundane and to you guys, but those moments were mattering to me in a big way.

She knew that we knew about Jem McKay and me. Myself personally mentioned it multiple times just to remind her that she was possibly covering for somebody that was treating her family like that.

I mean, what do you want me to say?

Absolutely.

There's no secret here that my husband is up when it comes to being a good husband.

You're not really throwing anything at me.

That I don't already know.

So she stood by her man. Yes, she did.

I think my husband screwed up, but I think my husband loves his wife and kids and didn't really know how to fix the mess he made.

The detectives held back their most important piece of evidence until the end of the interview. That's when, without warning, Detective O'Connor laid them in front of Jen. The photos of the intruder from the surveillance video.

If you just get a moment, just take a look. She glances down at him.

And looks.

Back up at us.

No size, no swallows. Nothing.

And she left.

Okay. Thank you very much.

Jen Green, who had every reason to hate Dan, still vouched for him. And that, detectives knew, wasn't good for their case. You thought you had this all rolled up in a gift box?

Well, I never think that, but I thought we had a good case. I call it a bump in the road.

But this bump in the road was about to turn into a sinkhole because attorney Warren Brown's next move would deal a potential death blow to the investigation and possibly set Dan free. There went your case.

It went out the door quick.

For true crime fans, nothing is more chilling than watching Dateline. Have you ever seen such a thing before? For podcast fans, nothing is more chilling than listening what goes through your mind.

When you make a discovery like that.

And when you subscribe to Dateline premium, it gets even better. Excuse me if I sound a little skeptical. Every episode is ad free.

Ooh, wow.

So this could be your ace in the hole.

And not just ad free. You also get early access to new intriguing mysteries and exclusive bonus content.

So what were you afraid of?

Dateline premium. Subscribe now on Apple Podcasts, Spotify, or datelinepremium.com you ready for what's coming? Summer 2018. The trial of Daniel Green was set to go. It was shaping up as the story of two Jens, the wife, providing an emphatic alibi.

Dan came upstairs, got in bed, and maybe lights out 1015 minutes after that.

And the ex girlfriend identifying the accused in that chilling video.

Does it look like anybody?

Looks like Dan?

Without direct evidence, Jennifer McKay's ID was make or break for the prosecution. No jury was ever going to hear about DNA or bloody footprint or anything like that.

It was about the video of Dan Green.

The defendant's parents thought Jennifer McKay's ID of their son from the security camera footage was a travesty. No way was that their Daniel. And during her interview with police, McKay seemed to have her own doubts.

But it's hard to tell. I don't know if it's just the way the image is. He just looks taller in this one than. I don't know, his nose is, like, pushed in more, not as angled like this looks. I mean, I see it, but I don't see it, if that makes any sense.

Daniel Green's defense attorney, Warren Brown.

It was a torturous process to get her to finally say, yeah, that's him. You didn't have to be a lawyer to see it. The q A of Jennifer McKay, which is this positive ID, and it's just laughable.

I'm gonna be blunt with you. We aren't in the I think business. What? We can prove business, and you're in the middle of it. And it's hard to look at someone knowing what the end result was. Yeah, we need to know if that's.

Him or not from these pictures. Yes, I would say this looks like him.

Defense attorney Tom Moronik Jr. She's worn down.

That's essentially what it was. They just beat her down long enough until she decided to identify Daniel Green.

So there was bias. They put the thumb on the scale.

Bingo.

It was so bad that it caused us to give it a shot at having it thrown out.

The defense filed a motion to keep McKay's identification of Daniel Green out of the trial, arguing a jury should never hear an ID that was coerced. The identification of Jen McKay is the big rap against your case that you guys were putting your thumb on the scale. You were influencing her decision.

I wouldn't change the thing that we did.

I know we did not put our thumb on the scale. I know we didn't do that.

But in a stunning ruling, the judge decided police did use improper suggestive methods to get Jennifer McKay's identification. And it should not be heard at the trial. That gutted the case against Daniel Green in the blink of an eye. Boy, there's a bad day for, huh?

It was. It was a tough day.

There went your case.

It went out the door quick.

If this doesn't get before a jury. Look, you don't have a case, do you?

That's it. And I was like, that's what worried me the most, because he was going to get out, and then he was going to disappear on him.

Prosecutors appealed, and Daniel Green was held in jail while the issue worked its way up to the Maryland Supreme Court. And there was another big ruling about potential evidence. Remember how investigators learned the brake line on John Hickey's car had been cut? They later got cell phone records linking Daniel Green to that.

That cell phone told us that during the time that those brakes were tampered with, that Daniel Green was in the area of Jen McKay's home, where John Hickey's vehicle was parked at the time.

But the trial judge said that wasn't relevant to the murder and threw out the cell phone records. Another blow to the state's case. All the wrangling over evidence delayed the trial date. And when COVID hit the wheels of justice ground to a halt. The delays went from months to years. They were tough times for the Hickeys and for the detective who formed a special bond with them.

Let me tell you something. I've been in Miss Hickey's situation. I've had that knock on my door.

Detective, what was the knock on your door?

1995. I'm going to cry. We get it together.

The knock on Val's door changed her life forever. It came from a police officer after her own grandfather was killed. An innocent, random victim of gun violence.

I remember the compassion and the care that those members gave me and my family when they were investigating my grandfather's death. So when I'm fighting, I'm not just fighting for John. I'm fighting for his mom. I'm fighting for his uncle. He bears his namesake. Like, those are the people I'm fighting for. Everyone that loved him.

Was that helpful for you to see her steal her spine in all of this?

Without her, I would have been lost. I wouldn't have known what else to do.

In September 2021, four long years after John Hickey's murder, Val Vaughn got a call. There was news, big news.

It was just like Christmas that day. It was literally like everything lined up, like, oh, my God. This is the break we needed. This is just what we needed.

When Jennifer McKay's identification of Daniel Green on the security camera footage was thrown out by a judge, the whole case seemed to hang in the balance until.

Jen Green says, I need to talk to you.

All the other Jen, Daniel Green's wife and Alibi wanted a meeting with prosecutors and detectives. What was this all about?

She comes forward and we meet. Prosecutor, myself and other detectives meet with Jen Green and she says, a lot has changed.

The changes for Jen had been seismic. Her husband's infidelity had been devastating. And when he was charged with murder, it was more than she could bear.

I don't live in a world where people say someone's being arrested for first degree murder. It was just unfathomable.

Unfathomable and also impossible because she claimed Daniel was in bed with her on the night of the murder. But according to Jen, that critical alibi came only after she was pressured by Daniel and his family, especially her father in law, Randy, who told know Daniel.

Said, you guys were in bed together and he was home that night and you're his alibi. And it's just constant from his family, just unrelenting.

Jen's first statement to police was unequivocal.

Like midnight, Dan came upstairs, got in bed.

But when detectives showed her three photos from the security camera, she froze.

The minute I saw him in this very distinct way that Daniel stood, I just knew it was him and I just stopped. Everything inside of me just. My heart stopped. Everything just stopped.

But at that moment, Jen did not identify her husband. And detectives say her face revealed nothing. She was stoic. Jen's thoughts were anything but.

It was just very scary and very surreal. And honestly, I don't know how I kept it together. I actually had a friend drive me downtown. And once we got away from this building, closer to the parking garage, I just collapsed in her arms.

It was an overwhelming moment. But Chen was still prepared to take an oath and be her husband's alibi.

I wanted to wholly believe that he wasn't capable of doing something like this, that my children weren't going to have this cloud over them for the rest of their life, that their stepfather and their father murdered someone.

But when the trial was postponed, she had a lot of time to think. And as the months passed, she started to waiver.

And I'm just in this world of back and forth know, was he in bed? Is that really him?

Over the next few years, Jen dedicated herself to changing her life. She started working full time as a travel agent and was able to support her family on her own, she says, she became a new woman, confident and independent.

I removed myself from having a relationship with Dan. I removed myself from having a relationship with his family. I was no longer getting calls from jail from him, reminding me that he was in bed. I was no longer getting the pressure from his family.

After a lot of soul searching, Jen reached a tipping point and says she was finally able to accept the truth about her husband. On the night of the murder, I.

Realized he was not home in bed.

It was a startling reversal, triggered by a cris of conscience.

And I needed my kids to see that doing the right thing is never wrong. And now I have to do the right thing, which is to tell the state.

And so, four years after she'd given detectives a powerful alibi for her husband, she was on her way now to tell them something very different.

I wasn't at all nervous or anxious. I was actually relieved to finally be able to talk to somebody and say, hey, here's the truth of the matter. Here's what's really going on.

They met in a restaurant, tucked away in a quiet booth.

She says, it was a lot going on and I want to apologize to you, but I can't be his alibi witness.

Can't be his alibi witness.

She said, he was not with me.

And there went Daniel Green's alibi. Jen's original story had been the bedrock of her husband's defense. Her new version turned her into a star witness for the prosecution. And the jury is going to decide what to make of you.

Exactly.

She told it one way this time, that he was the alibi, and now she's saying exactly. This guy's guilty, guilty, guilty.

I did say that he was in bed, but I was coached. I was reminded repeatedly that he was in bed.

A jury would have to decide. But Jen's reversal looked like a tremendous blow to the defense and to Daniel Green's parents. This is a huge bombshell. Yes. Was it a betrayal or is that too strong a word?

No, it's a betrayal.

I think what she did is very calculated.

Calculated and according to the Greens, all about the fact that Jen was now asking for a divorce and Daniel refused to agree to her terms.

She demanded everything. It was totally unreasonable.

I want to be taken care of the rest of my life. And Daniel, you're going to do this for me. And if you don't do that, you're going to spend rest of your life in prison anyway, because I'm going to make that happen for you.

Vindictive yes.

I don't need him or his money to survive, but he should be responsible for his child. And to think that I'm some kind of vindictive, know that's ridiculous. Like, come on.

Especially galling for the Greens was the idea that they pressured Jen to be Daniel's alibi. You deny that?

It never happened.

The Greens insist Jen's original version, given at the family's first meeting with defense attorneys, was the truth, and she could not have been more clear.

Jen blurts out, Randy, he was with me. I remember that day perfectly.

A betrayal to the Greens felt like a gift to the Hickeys.

I thought, oh, lord, thank you, lord, for helping me. And I looked up and I said, johnny, thank you for putting a bug or whatever in anybody's ears to get this going.

There was another huge development in the case, and it was good news for the Hickeys and the prosecution. The Maryland Supreme Court decided a jury could hear Jennifer McKay's identification of Daniel Green. Prosecutor Rita Wistoff Ito.

If we had lost, we might have not had a case anymore. The case might have had to be dismissed.

At that point in time, the state's case looked strong, but the defense was primed to attack. Jen Green's high stakes reversal would become high drama in the courtroom. Warren Brown would see to that.

Her motive now was to hurt her husband and really not provide the truth. And so we felt pretty good that their case was riddled with reasonable doubt.

After years of drama and delays, it was time to put that confidence to the test at the trial of Daniel Green. Six years after John Hickey's murder, the trial of Daniel Green got underway at the Mitchell courthouse in downtown Baltimore. Let's talk about the trial. John, are you there?

I'm there. I was there whole time. I was not going to miss it.

It was a circumstantial case, but prosecutor Rita Wistoff Ito thought it was a strong one.

There was just so many things in this case. Video footage was very good. It's clear it's close. You know, the black pickup truck testimony of Jen McKay and Jen Green were very key.

The prosecution also had a treasure trove of new evidence. Jen Green had discovered in a hidden file on her laptop, which the prosecutor believed her husband was using searches on how to make untraceable calls, which seemed to connect the defendant to those harassing calls to Jennifer McKay. And according to the prosecutor, there were lots of searches that showed Daniel Green's obsession with the man he was accused of murdering.

You just see this progression and his searches of trying to figure out who John Hickey was, where was know his actual address. Based on those searches, he knew where John Hickey lived.

Of course, the jurors got to see that critical security camera video, and they heard the two women who knew Daniel Green intimately identify him. And not just from his face. Something else gave him away.

I saw my husband just standing there with his arms in his pockets like he did, looking up. And I knew it was him.

When prosecutor Wistof Edo looked at footage of Daniel Green pacing in a police interview room with his hands in his pockets, it was a revelation that footage.

Of him walking around in that interview room compared to the video footage of him pacing around in the back of that house. That's Daniel Green. There's no doubt.

And when Wistof Edo showed the jury that interview room footage, Warren Brown realized he had a problem.

I was ready to knock over the picture of water just to distract the jury. It was certainly the strongest evidence to bolster Jennifer McKay and Jennifer Green's assertion that that's him on that video outside this man's house.

When defense attorney Brown got his turn, he told the jury that in a rush to judgment, detectives neglected obvious leads, like that mysterious passport and the palm print on the windowsill.

They wanted to close this matter and move on to another one. And so there wasn't much due diligence. It wasn't checking all possibilities.

We weren't going to get fingerprints or DNA, for that matter, because the video showed who we believe is Daniel Green wearing gloves at the time.

Did you talk to passport guy? Did you get his story? Because some people on the defense side say he wasn't really looked at as closely as you would have.

He did not look in any way, shape, form like Daniel Green or the person in the video.

Everything led to Daniel. There was nobody else to look for.

The defense believed its best opportunity was to discredit Jen Green. Brown subjected her to a withering cross examination, hoping to show the jury she was testifying against her husband out of revenge. Jen rebuffed Brown's questions. But then something extraordinary happened when she.

On the witness stand, she lost her composure.

It was an explosive moment. Jen on the witness stand, eyes fixed on her husband.

Dan just had this smirk and this glare, and it was one that I was very familiar with. It was the disapproving, shut your mouth. Know, your. I just, I just said, you can stop looking at me like that.

You told him.

I looked right at him. And the judge cleared the courtroom, and I got really emotional. Because I thought, oh, no. I let the jury see me angry at him. And that was what the defense was trying to paint.

I loved it because we wanted to say to the jury, you see how much she hates him. You can see it in court. She's got a motive to come in here and lie. And we were like, good man. We're doing pretty well with this thing. We're doing pretty well.

Daniel Green's parents thought the defense could have done better. They wanted the jury to see a side by side comparison of the enhanced security camera still and Daniel's mug shot. Proof positive. They say that Daniel's not the killer.

The guy in that surveillance video is not Daniel Green.

Which is your opinion of this image, right?

Yes, but the jury, why is that.

Any different than Jen McKay's opinion or my opinion?

Look at that picture. Look at that picture. Look at that nose. Look at that nose.

A lot of people say this couple cannot believe that their son did this thing and they're living in this bubble. And that's what they need at this point just to get through.

That is not a bubble. That's a very vivid picture.

What's the motivation for Daniel doing this to this man?

If I thought my son did it, I'd be the first one to say, daniel, plead guilty, ask for mercy.

But the jurors would be the finders of fact. And after deliberating for just 3 hours, they reached a verdict. Daniel Green, guilty of first degree murder. Also guilty of home invasion and firearms charges.

I was like, thank you, God. We got the justice. And that was it.

We've got him. We're done. Sentence him. Put him away.

Daniel Green was given a life sentence. His family is planning to appeal. Valvone is retired now, but the verdict meant justice was served on her 56th and final case.

I cried. I literally sobbed. This is my last trial. This is my last trial as the primary detective.

The two jens at the heart of the story have been rebuilding their lives. Jennifer McKay got married and had two children. Jen Green says she can hold her head high because ultimately she did tell the truth. She also feels proud of the way she confronted Daniel in court.

Even though I had that moment where I thought I screwed up, I just felt like, you don't have any power over me anymore. You have not earned that. And you don't get to have that.

Did it feel good to let loose with a thought?

It did. It felt really good.

In a story with many victims, Jen does not want to be counted among them.

I hate the word victim. I'm not a victim. I'm a survivor.

She is a survivor. We all are survivors. We will survive this.

I love you, baby.

You survivors still dealing with a terrible loss, but grateful for reminders of the young man they loved. John, I can't help but notice down by your feet, you get a firefighter's helmet. What is it? Tell me its story.

This is who my nephew was. He was a person of character. He was a firefighter. He would give anything, do anything for anybody.

That was his gear.

This is his helmet?

Yes.

I keep it on a table as a reminder of who my son was for me.

That's all for this edition of DateliNe. And check out our talking Dateline podcast, Dennis Murphy and Josh Mankind. It will go behind the scenes of tonight's episode, available Wednesday in the Dateline feed. Wherever you get your podcasts. We'll see you again next Friday at nine, eight Central. I'm Lester Holt. For all of us at NBC News, good night.