An inquest jury has sharply criticised a prison over the death of a Chesterfield man who was told he was to be freed - only to be returned to his cell.
Andrew Brown, 42, had been on a list of inmates needing special checks because of mental health concerns, the eight-day hearing was told.
But the checks had ended by September 12, 2017, the day he was found hanging in his cell. He died in hospital five days later. In a month, four more inmates had died.
The 11-member jury heard that Mr Brown was an active Christian but had been banned from a church after making a series of allegations.
He also toured Chesterfield town centre raising a petition protesting about Derbyshire police.
The Nottingham inquest was regularly attended by his brother Kevin, 40, who lives in Chesterfield. He said later: "It was shocking to hear how unsafe it was.
"My brother was failed badly by HMP Nottingham. It would have been obvious to everybody how vulnerable he had become.
"He was denied the mental health care he needed. He was let down by those who should have been keeping an eye on him."
After returning a narrative conclusion, the jury criticised the prison's performance at the time of Mr Brown's death, answering questions posed by Assistant Coroner Laurinda Bower.
They said: "Andrew did not receive appropriate and timely assessment and support from the mental health team.
"There was an inadequate level of experienced staff during his time in the prison. There were staff shortages, staff assaults, prisoner assaults, violence, drugs and self-harm.
"Staff were doing their best but there were too many pressures."
The jury said that Mr Brown should have been put back on a mental health review on the day he was found hanging.
Jurors said that Mr Brown's cell bell was not answered within the five minutes ordered by the governor, suggesting it was left for 42 minutes, which was "completely unacceptable."
They felt that he suffered from being unable to attend Bible studies and Christian services but were "unable to determine his intentions" when putting a bed sheet round his neck.
The jury said that mental health review system was "adequate" but added: "It was not used or followed correctly because of inadequate quality assurance, inadequate training and inadequate audits due to failure of governance."
Governing governor Phil Novis, who took over after five inmates died, said that major improvements have been made.
The prison was able to recruit 50 more staff. With departures, this worked out at around an extra 30 or 35.
At the same time, the prison capacity has reduced from around 1,060 to 800.
Mr Novis told the hearing: "I can't emphasise enough - safety is the number one priority for us. It is the number one goal."
Keith Attwood, the new head of safety and safeguarding, said that 90 per cent of staff have been trained to identify prisoners at risk of "suicide or self-harm."
He also said that senior staff have improved the review system for people who fall that category.
"We are concentrating on risk factors, triggers and protective factors.
"This is what is going to save someone's life," added Mr Attwood.
Health care nurses now work seven days weekly.