A Maryland state trooper was injured early Saturday morning after his patrol vehicle was struck on the outer loop of the Capital Beltway at Allentown Road in Prince George’s County.

Maryland state police say the officer, Angel Ortiz, a seven-year veteran of the force, was struck from behind at around 1:30 a.m. while Ortiz was investigating a disabled vehicle. Police say Ortiz sat in his marked car with his emergency lights as the vehicle’s motorist changed a flat tire. Ortiz had also placed flares around the vehicle.

Ortiz was taken to a nearby hospital where he was treated for his injuries.

Police say the driver of the vehicle that struck the patrol car was Maurice Gresham, 51, of Lanham. Gresham was charged with driving while under the influence of alcohol and arrested at the scene.