Tucson police are investigating a Saturday night homicide in midtown.

George Martinez, 59, was found unconscious and with "obvious signs of trauma" by his roommate around 10:30 p.m. in the 2200 block of East 19th Street, police said.

He was pronounced dead at the scene.

Police said there was no sign of forced entry and Martinez' 1994 Ford Explorer is missing. The white SUV has Arizona license plate ACV8135.

Anyone with information on the vehicle is asked to call 911.