Police are interviewing 18-year-old DeAndrew Hamlin, who was arrested Monday night after briefly fleeing from police and crashing Marcum's SUV in northwest Washington. Marcum was found dead Monday morning.
The documents indicate a straight-edged weapon was used to cut the screen of a basement window of the house on Massachusetts Avenue, where Marcum lived alone.
The recovery of the stolen Jeep Cherokee broke the case open. Hamlin first told detectives he got the keys from a friend, then changed that to his brother.
So far, Hamlin is only facing charges related to the stolen vehicle and the police pursuit.