Gilbert Young, 20, died on 12 March after being discharged from hospital in Norwich. He had overdosed on methodone, a heroin substitute, pushed his head through a reinforced glass window and tried to slash his wrists.
Mr Young was in the care of the Greater Manchester police witness protection scheme. He had a history of mental illness and attempted suicide. Last week, he would have been the chief prosecution witness against Peter Pasquill and William Holohan, who were alleged to have hired Mr Young in May as their driver for a burglary in Bolton. Young had admitted the burglary but was remanded for sentence until after the murder trial.
Instead, Mr Pasquill, 33, and Mr Holohan, 36, who denied the charges, were discharged at Manchester Crown Court. The Crown said Mr Young, on whose evidence the prosecution depended, told police he drove Mr Pasquill and Mr Holohan to the home of William McGrath; he alleged they tied-up their victim after he disturbed them.
Mr McGrath died from asphyxiation, choking on his false teeth after a sock was thrust into his mouth as a gag.
'The prosecution depended entirely on what Young said and he apparently deliberately took a drugs overdose in circumstances which probaby indicate he intended to take his own life,' Peter Openshaw QC, for the prosecution, said. There was forensic corroboration of Mr Young's statement, but other evidence was insubstantial.
His father, Malcolm Young, yesterday claimed Greater Manchester police should have taken greater care of his son after sending him in August to a 'safe' house in Norwich.
'I told a detective before Gilbert went on the protection scheme that he had a history of mental disturbance. He had twice attempted to take his own life with an overdose of tablets and had been admitted to a psychaitric ward. I asked the police to keep an eye on my son. They did not. He had no history of taking hard drugs. The police didn't visit him. As far as I know, they didn't protect him.'
Mr Young's solicitor, Rex Makin, said the case was an indictment of the witness protection scheme. 'Leaving aside the humanitarian issue, the police had a selfish interest in protecting their witness and a duty to Mr McGrath's killers to see those responsible brought to justice. Instead, they may have caused a miscarriage of justice.
'Instead of the Home Secretary seeking extra remedies to fight crime, he should ensure those at the disposal of the police are used responsibly.'
Greater Manchester police said it would not comment on a case which might be subject to a complaint. A date has yet to be fixed for Mr Young's inquest.Reuse content