Police say an armed man ordered an Ohio highway patrol trooper out of his car before the trooper shot him to death.

The Ohio State Highway Patrol says it's unclear why 22-year-old Justin McHenry approached the officer around 1:30 a.m. Sunday in Celina (suh-LEYE'-nuh).

Investigators say the trooper was completing paperwork in his parked cruiser when McHenry parked nearby, approached on foot and ordered the trooper to get out. Investigators say McHenry then pointed a 9mm handgun at the trooper.

Patrol officials say the trooper tried to disarm McHenry before shooting him.

McHenry died later at a hospital. The trooper was uninjured.