PITTSBURGH — A post-mortem exam shows a police dog died of heat stroke after being left in his handler’s parked squad car for nearly four hours, according to a police chief.

New Castle Police Chief Thomas Sansone isn’t identifying the officer who was handling Chico, the 6-year-old Dutch shepherd that died Saturday. The dog was found unresponsive in the car parked outside the station. The Lawrence County district attorney is also investigating to determine whether criminal charges are warranted, Sansone said.

Investigators determined the dog was left in the car for about three hours and 45 minutes, based on interviews and a review of surveillance video from the police parking lot where the car was parked, Sansone told The Associated Press on Thursday.

Sansone said the dog was one of four owned by the 37-officer department. Chico was cross-trained for use in drug cases, searches and for routine foot patrols and crowd control. The officer’s internal disciplinary hearing likely won’t be held for two weeks.