By Peter Lennon

A television investigation has cast doubt on the murder conviction of a man with mental problems.

Oliver Campbell has been in jail for 10 years of a life sentence for the murder of an East End off licence owner, Baldee Hoondle, during a robbery in July 1990.

Although Campbell confessed to the crime under interrogation, his lack of legal representation at the time and the strategy employed by the police to gain a confession from a 20-year-old man of limited mental ability have already been said to cast doubt on the case against him. Campbell has since persistently protested his innocence.

Next Sunday the BBC programme Rough Justice will present an analysis which challenges the prosecution's case. It contains a statement from an accomplice to the robbery which, if true, exonerates Campbell, and it claims to be able to name the person who fired the fatal shot.

A crucial piece of evidence was a baseball cap dropped by the murderer as he ran from the off licence. During interrogation, the police told Campbell that his fingerprints were found at the scene and the hairs on the cap matched his. In fact, the forensic tests had not been completed. When they were, no fingerprints of Campbell were found and the hairs were not his.

There is, allegedly, no forensic evidence linking him to the scene.

Later, at an identity parade, neither of the two witnesses to the crime picked out Campbell as the man in the cap. The two robbers were said to be 5ft 10in or 5ft 11in; Campbell is 6ft 3in. Campbell is left-handed while the shot was fired most probably by a right-handed man. Campbell had lived in a number of foster homes and is claimed to be borderline mentally defective.

An accomplice to the crime, Eric Samuels, who was sentenced to five years for robbery, said that Campbell was not the killer. But his evidence was never heard in court.

Campbell may have contributed to the police case by admitting to knowledge of the crime which he had actually got from a BBC Crimewatch programme.

* Rough Justice: If the Cap Fits was shown on BBC TV on 6 January 2002