Police actions contributed to the death of a man with epilepsy after he was restrained face down in a police van, an inquest jury has ruled.
The jury found the officers were ill-equipped to deal with Duncan Tomlin's asphyxia after he collapsed during a struggle in West Sussex in 2014.
The six women and four men said neglect contributed to his death, which was in part due to how he was restrained.
Police representatives said the ruling showed they had done nothing wrong.
Mr Tomlin, 32, died in hospital two days after losing consciousness during the arrest in Haywards Heath in July 2014.
The inquest in Crawley heard he had been wrestled to the ground and sprayed with an incapacitant after punching a police officer in the face.
He was handcuffed behind his back, placed in leg restraints and held face down before being carried into the police van.
The jury said Mr Tomlin died from "cardio-respiratory failure due to restraint in a prone position and the effects of cocaine and methadone".
But it noted: "Duncan should have been moved on to his side earlier."
The jury added that police training relating to positional asphyxia had been inadequate and said: "The death was contributed to by neglect."
West Sussex assistant coroner Elisabeth Bussey-Jones said she would be issuing a report aimed at preventing future deaths in similar circumstances.
After the hearing, the family's solicitors said: "The jury's conclusion... is a damning indictment of the police's action in this case and the way police treat vulnerable people generally."
Inquest, a charity that works with families after a death in custody, has urged the Crown Prosecution Service to reconsider its decision not to prosecute the officers involved.
But Sussex Police Federation said in a statement the conclusion "proves that the Sussex Police officers reacted appropriately to the circumstances they were faced with and did nothing wrong".
"The officers did their very best to save Mr Tomlin's life."