The way in which a father was restrained by police "more than minimally" contributed to his death, an inquest jury has found.
Leon Briggs, 39, was detained under the Mental Health Act and taken to Luton police station in handcuffs and leg restraints on 4 November 2013.
He was suffering a psychotic episode and had taken amphetamines. Officers responded after being told he was darting into shops, talking to himself and wandering into traffic.
Police subsequently restrained Mr Briggs in a face-down position in the street for more than 13 minutes.
Witnesses said they heard him call out "please help me", while another described him as being "like a child crying out for a toy".
Dexter Dias QC, representing the Briggs family, said Acting Sgt Loren Short and PC Geoff Bennett used "excessive force" to restrain Mr Briggs in a "very dangerous fashion".
Later, at the police station, officers attempted to resuscitate Mr Briggs after he had been silent for a few minutes.
He died about two hours later at Luton and Dunstable University Hospital of "amphetamine intoxication in association with prone restraint and prolonged struggling", senior coroner Emma Whitting said.
There was a secondary cause of heart disease.
A jury of 10 at the inquest in Milton Keynes found that while officers did "reasonably believe" it was appropriate to use force to restrain Mr Briggs, "inappropriate weight" was used against him "at times".
The jury added that officers' alleged failure to recognise that Mr Briggs was in a state of medical emergency, and failure to monitor him in the police van and cell, also contributed to his death.
Prior to the inquest, paramedics from the East of England Ambulance Service NHS Trust, who went to Marsh Road where Mr Briggs was restrained, had already admitted failing to check Mr Briggs' vital signs or take him to hospital in an ambulance for treatment.
Mr Briggs' mother, Margaret Briggs, 67, said the jury's conclusion that the incident fell short of a verdict of unlawful killing has "not brought the closure we wanted".
Mr Briggs was of mixed ethnicity. The family added that there is "no justice for people like Leon" and they "think race is very much an issue in this".
Deputy chief constable of Bedfordshire Police, Trevor Rodenhurst, said the jury had "identified a number of significant failings by the police which contributed to the death of Mr Briggs and for this we are truly sorry".
He added: "This inquest focused on a period of 36 minutes as we responded to public concerns for Mr Briggs who was suffering a drug-induced psychosis triggered by amphetamine levels described by one expert as being 'off the scale'.
"Unbeknown to officers he also had a serious underlying heart condition. There is no easy way of managing such a situation.
"The attending officers chose to restrain him so he could be taken to a police custody suite where he could be assessed.
"By the time it became apparent that he was a medical emergency it was too late to save him, despite their concerted efforts.
"We have made extensive changes since 2013 but we remain absolutely committed to working with the coroner and all of our partners in order to identify and make any necessary further improvements."