His brain damage as a baby lies at the heart of Oliver Campbell's bid to clear his name. It was here after his arrest at 19, he confessed to a fatal shooting, a false confession he says he was bullied into by detectives without a solicitor to advise him. Why did you confess?

Under police pressure and under duress.

Do you remember how that felt at the time?

It's like someone put in your room and there's no way out of it.

This was the scene of the crime in East London. Today, it's a restaurant. In 1990, it was an off license. Police. Two men tried to rob it, and there was a violent struggle. The owner, Baldev Hoondal, was shot dead. Campbell's lawyers will argue that police pressed him to make a false confession. Jurers weren't of his full mental health problems. He was mistakenly identified by a witness. The name of the real gunman was given to police, and the gunman was right-handed. Campbell is left-handed. Campbell was freed on license after 11 years and has campaigned to establish his innocence ever since. You've been free for 22 years.

I'm not free. I'm still a prisoner in the criminal justice system and a prisoner under the Home Office. They can recall me any time without going to the police station or court, straight back in prison.

If the appeal judges agree that Campbell was not the killer, then police will be under pressure to reopen the murder investigation. Martin Brunt, Sky News.