The risk a drug-using schizophrenic posed to others was not disclosed to the organisation that housed him in shared accommodation where he killed a fellow resident, a report has found.

A long-awaited NHS report into the fatal attack by Adrian Johnson, 27, on Robert Lewis, 49, at the home in Cheam Road, Sutton, on May 4, 2010, has made 11 recommendations on how to prevent a similar event in the future.

But the report, published last week, did not conclude the killing could have been avoided.

Father-of-two Mr Johnson stabbed Mr Lewis, and assaulted another man at the home for vulnerable people.

Mr Johnson, a former warehouseman, charged with the attacks, was found hanged in a cell at Belmarsh prison just over a week later on May 13.

NHS London launched an independent investigation into his care and has finally published the results – making 11 recommendations largely to the South West London and St George’s Mental Health NHS Trust (SWLSTG).

It shows information about Mr Johnson’s risk to himself and others, his self harm, paranoia and illegal drug use were not disclosed on his housing application.

This meant Croydon Churches Housing Association (CCHA), which ran day-to-day affairs at the home, were unaware of the potential risk he posed to other more vulnerable residents.

The report recommends the SWLSTG trust review its system to ensure adequate focus on mental state, risk assessment and carers’ needs and when professionals write to support an individual’s housing application – information regarding “potential risk areas” is disclosed.

The report reveals that Mr Johnson had taken illegal drugs from the age of 12, had a criminal record and had tried to take his own life on multiple occasions.

The report stated over the weekend of May 1 2010, just before the incident, his family reported that he was agitated and had run out of medicine – which they tried unsuccessfully to obtain for him.

Following his death his friends described him as a gentle and caring father.

The independent inquiry concluded that the incidents were not predictable nor preventable. It criticised the SWLSTG trust for not sufficiently committing itself to the investigation process considering the gravity of the incident.

A spokesman for the trust said: “The trust has since strengthened the leadership team and ensured accountability for serious incidents is part of day-to-day responsibilities to address those comments.

“We have always taken seriously incidents regarding our service users and have in place a robust and comprehensive process to investigate serious incidents fully.”

A spokesman for CCHA, which is no longer the provider of care for the scheme, said: “We are pleased this investigation has now been concluded and that clear recommendations to strengthen the information sharing between health professionals and housing providers have been made.

"Our thoughts are once again with the families of both men affected by this tragic incident.”

NHS London said the trusts were working hard to fulfill the recommendations.