Prosecutor's expert told grand jury police did not kill Daniel Prude

Prosecutors overseeing a grand jury investigation into the death of Daniel Prude last year in Rochester, New York, undercut the case for criminal charges with testimony from a medical expert who said three police officers who held Prude to the ground until he stopped breathing didn't do anything wrong.

Dr. Gary Vilke told the grand jury that Prude, a 41-year-old Black man, died of a heart attack caused by the medical phenomenon known as excited delirium. He said the officers' actions, which included placing a hood over Prude's head, had no impact on his breathing, according to transcripts of the proceedings made public Friday. A medical examiner ruled Prude's death a homicide due to asphyxiation from a physical restraint, with use of the drug PCP as a factor. There is no universally accepted definition of excited delirium and researchers have said it's not well understood.