Savannah, Missouri, Police K-9 Horus died last week after being left in a vehicle following an overnight shift.
The Savannah Police Department is currently down to just three officers and Horus was their fourth, KCTV reports.
Andrew County Prosecutor Monica Morrey has requested that the Missouri State Highway Patrol investigate the dog's death.
Chief David Vincent said death is considered an accident at this time but the investigation is ongoing.