An unauthorised strip search in police custody was the "final nail in the coffin" for a man who killed himself the next day, his father has said.
Boatbuilder Logan Peters, 22, from Millbrook, Cornwall, was found hanged the day after being released from a Plymouth police station.
His treatment has been criticised in a report by the Independent Office for Police Conduct. (IOPC).
Devon and Cornwall Police said it had acted on recommendations by the IOPC.
Mr Peters was arrested on suspicion of criminal damage in May 2014 after a night out and taken to Charles Cross police station.
While in custody Mr Peters, who had mental health issues, tried to take his own life, but his behaviour was dismissed as "attention-seeking", a 2016 inquest heard.
'Worst possible treatment'
After being charged and released, Mr Peters was found dead at his home the next day.
Speaking after the IOPC's report was published, Mr Peters' father Robert told the BBC: "The strip search put him over the edge.
"When you take your own life you think there is no way out and the police were part of that.
"Logan was being respectful and did not kick off.
"He needed assistance and protection, but he was treated in the worst possible way."
The inquest jury concluded officers had used unlawful force and carried out the unauthorised strip search.
Jurors said it was "extremely likely" the treatment Mr Peters endured "had a negative impact on [his] physical and psychological wellbeing".
The IOPC said the force has made a number of changes in response to its report, including updates to its custody procedures.
One officer was given "management advice" and misconduct was proved against another, the watchdog said, but no action was taken "due to a recognised lack of training in how to conduct strip searches".
Another officer had retired from the Devon and Cornwall force and no further proceedings could be held.
IOPC director Catrin Evans called it an "incredibly sad case" and said a "number of interactions" on arrest and detention of Mr Peters "could have been handled differently".
Devon and Cornwall Police said in a statement that the force's "thoughts remain with Mr Peters' family, friends and everyone affected by Mr Peters' death".
It said changes as outlined in the IOPC's report had been made.
"We pride ourselves on delivering a professional service of the highest possible standard and are constantly seeking to improve our practices to ensure public safety," it said.