Detectives say a Shirley man died in police custody in Selden.
They say officers performed CPR and used an AED on Quinn Harrison after a detention attendant found him lying on a cell bench in an awkward position on Monday night.
The 39-year-old was taken to Stony Brook University Hospital, where he was pronounced dead, according to detectives.
They say he was being held after being arrested on two bench warrants and a drug charge.