An NHS trust has been told to take action after a coroner found it did not assess that a man was suffering a mental health relapse just two days before his death.
Jason Lennon, 37, died on July 31, 2019 after being restrained by security staff at the ExCeL Centre in the Royal Docks.
A jury inquest was held into his death, which concluded on February 11 this year.
Coroner Nadia Persaud has now written a prevention of future deaths report, which has been sent to East London NHS Foundation Trust (ELFT) with concerns about the trust's actions relating to the case.
The report said police received 13 999 calls in a 35 minute period on the morning of Jason's death, describing his behaviour as "unusual and confrontational", assaulting bystanders and walking into traffic.
He had proceeded to Prince Regent Lane from his accommodation, the report said, but officers were directed to the ExCeL on attendance.
Jason had entered the venue as a trespasser in pursuit of a member of the public and was restrained by security staff.
But he was found unresponsive by police and died in hospital.
Jason had a history of brain injury and schizophrenia, the report said, and had relapses resulting in acute psychosis and an increased risk of harm to himself and others.
He was assessed by support staff to be in relapse after he assaulted another resident at his accommodation on July 28.
The report said ELFT's community recovery team (CRT) reviewed Jason the next day but said he was mentally "stable" and "not in crisis".
Jurors gave a narrative conclusion and said failures in Jason's community mental health care contributed to his death.
In the report, Ms Persaud wrote that the CRT's review of Jason on July 29 was "flawed".
"(It) failed to assess that Jason was in relapse and was a risk of harm to himself and others," she added.
Ms Persaud said CRT staff did not effectively review medical records before assessing him.
She also wrote that the CRT "failed to effectively monitor whether Mr Lennon was on a care pathway appropriate to his needs".
Expert psychiatric evidence given at the inquest said Jason was suitable for the Care Programme Approach mental health pathway and the report said "the use of this pathway would have reduced the risk of an acute deterioration in his mental state".
Ms Persaud also said ELFT had not completed an action plan by February 6 recommended following its investigation into Jason's death.
She said this was due to "errors attributable to the trust's governance team".
An ELFT statement said: "In the aftermath of Mr Lennon's death, the East London NHS Foundation Trust carried out a review of Mr Lennon's care.
"Subsequently, a number of improvements to how care and support is managed were made.
"Our thoughts are with Mr Lennon's family and friends at this difficult time."
In their conclusions, jurors also said the restraint used by security officers contributed to Jason's death.
They found that "although the use of restraint by the security officers was necessary, the extent and manner of that restraint was unreasonable", the report said.
According to the ExCeL, none of its staff were involved in the restraint and that the security staff involved were employed by Secure-Ops.
A Secure-Ops spokesperson told the Recorder: "Everyone at Secure-Ops would like to pass on our condolences to Jason’s family and friends.
"The incident on July 31, 2019 was extremely shocking and distressing for all concerned.
"All our door supervisors are Security Industry Authority accredited and at the time of the incident, they had undertaken all the mandatory training in relation to physical restraint.
"We continue to do everything we can to ensure the safety of clients and the public at future events."
Following the inquest, Jason's mum Vevine said: "Jason was a loving and thoughtful son. Everyone who knew him described him as smiling, gentle and kind.
"The mental health teams should have done better and we are heartbroken to have lost Jason in such a violent and shocking way as a result – we pray this doesn’t happen to anyone else."
Lucy McKay, from charity Inquest, said ELFT must ensure action is taken following the concerns raised by the case.
She added: "Jason’s ill health should never have been allowed to escalate to this crisis point, putting him and the public at risk."
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