The independent inquiry recorded a number of errors in the treatment of John Barrett, 42, who was allowed to walk out of a secure unit despite a history of violence and mental illness.

Barrett repeatedly stabbed Denis Finnegan, 50, a retired banker, as he cycled through Richmond Park on September 2, 2004. Two days earlier, Barrett had been admitted to the Springfield Mental Health Hospital in Tooting after hearing voices in his head, and was in a medium- security unit.

The inquiry named Gillian Mezey as the psychiatrist who made the “seriously flawed” decision to grant permission by phone for Barrett to have an hour’s unescorted leave in the hospital grounds, even though she had not assessed his condition.

Robert Robinson, the lawyer who chaired the inquiry, was even more critical of management at the hospital and the South West London and St George’s Trust, which runs it. He said that clinical decisions were often unsupported by evidence and were rarely challenged by colleagues.

In a direct attack on the judgment of Dr Mezey and other clinicians, he said that staff had been too reluctant to intervene against Barrett’s wishes, going along with what he wanted in the hope of maintaining his co-operation. That was con- trary to all legal and clinical guidelines, but management at the trust had failed to take action. “The trust knew there were problems and didn’t do anything about them,” he said.

Many senior managers have been replaced. In conclusion, the 422-page report casts doubt on whether the new senior staff at the trust were up to the job and recommended that a new team of experts be sent in to force through change. “We doubt whether there is the managerial capacity within forensic (psychiatric) services or the wider trust to achieve the necessary changes,” it said.

It called for the secure unit at Springfield hospital, in which Barrett was treated, to be closed. The trust has rejected this advice.

Dr Mezey, who is also a police adviser on domestic violence and murder, is still employed by the hospital but no longer deals directly with patients. Nigel Fisher, chief executive of the trust at the time of the murder, has been promoted to a job at the Department of Health, where he advises hospitals on how to win foundation status.

Peter Houghton, the trust’s new chief executive, said now that the inquiry had been published he would explore whether disciplinary action would be taken. Along with the criticism of the health trust, the inquiry condemned the independent Mental Health Review Tribunal that allowed Barrett to leave secure care at Springfield hospital in 2003, only a year after he had stabbed three people at random at an out- patient clinic in St George’s Hospital. One man almost died in the attack.

The tribunal spent only 45 minutes considering the case, examining reports from Springfield hospital that recommended conditional discharge.

At the time of the 2002 stabbing he was considered so dangerous that he was placed under the direct care of the Home Office. Only the Home Office raised objections to his release, making it clear that it did not want him back in the community.

Barrett failed to adhere to the conditions laid down for his release, including taking his antipsychotic drugs and staying off recreational drugs. The conditions were not monitored or enforced, and he began to behave erratically and complained of hearing whispering voices. That led to his returning to Springfield hospital on August 31, 2004.

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