An off-duty Bladensburg police officer who died Saturday shot himself before his marked patrol vehicle crossed a highway median strip and crashed into another car, according to Anne Arundel County police.

Brian Johnson, a nine-year veteran of the 20-member police force in Prince George’s County, suffered a gunshot wound to his upper body, police said, and his death has been ruled a suicide. Authorities did not say if the bullet or injuries suffered in crash caused his death.

The crash occurred about 9 a.m. on Route 100 near Catherine Avenue in Anne Arundel County. Police said that the officer was driving east when his cruiser crossed the median and struck a vehicle heading west. The driver of that car was treated at the scene for minor injuries.

Johnson, who was in his 30s, was taken to Baltimore Washington Medical Center, where he was pronounced dead. Police at the time said Johnson may have suffered a medical issue that caused him to lose control. On Monday, they said it was a gunshot wound.

Johnson also was a volunteer firefighter in Bladensburg. On its Web site, the fire company paid tribute to Johnson and noted he had a wife and children.