Neglect contributed to the death of an epileptic man after he was restrained in a police van five years ago, an inquest jury has found.
Duncan Tomlin, from Oxfordshire, died in hospital two days after the incident in Haywards Heath in July 2014.
Mr Tomlin was wrestled to the ground after punching a police officer in the face.
The 32 year old was placed in restraints and held face down on the floor before being carried into a police van.
Officers continued to hold him face down on the floor in the van before he collapsed.
The jury at Crawley Crown Court found that Mr Tomlin died from "cardio respiratory failure due to both restraint in the prone position and the effects of cocaine and methadone."
They said that officers show "no urgency" to move Mr Tomlin, adding that "Duncan should have been moved onto his side earlier."
They found police training relating to 'positional asphyxia' was "inadequate", concluding that Mr Tomlin's death "was contributed to by neglect."
The Crown Prosecution Service (CPS) previously decided not to prosecute the Sussex Police officers involved.
Four were cleared of allegations of gross misconduct at a police disciplinary hearing.
Relatives and friends of Mr Tomlin hugged after the ruling was read out.