AURORA, Ill. -- An armed hospital patient who asked officers to shoot him during a standoff in an acute-care unit was killed by police gunfire, authorities said Sunday.

Johnnie Russell, 58, of Aurora was found dead on the floor of his room at Provena Mercy Medical Center after a 41/2 hour standoff with police ended in gunfire.

Police initially said it appeared Russell died of a self-inflicted gunshot wound, but later acknowledged that is was unclear if Russell fired his weapon.

An autopsy performed Sunday shows that Russell was killed when a single bullet from an officer's weapon struck him in the face, police said. Russell was also struck in the arm and side.

Russell was fatally wounded when he opened his hospital room door at about 1 p.m. and raised a loaded, two-shot Derringer handgun in a threatening manner toward police, police said.

"At this time, the investigation indicates that the officer who fired his weapon was justified in his actions," police said in a written statement.

Police say an officer at the hospital responded to a report of an "unruly patient" and found Russell in his room armed with the handgun. The officer immediately stepped away from the room and cleared the floor while calling for backup and monitoring the door of Russell's room, authorities said.

Russell later agreed to release a 71-year-old male patient who was also in the room. But a standoff ensued and officers reported hearing Russell say he wanted police to shoot him, according at authorities.

"He continually made threats to harm himself and police officers," police said Sunday.

The police officer, a 12-year veteran of the force, has been reassigned to administrative duties pending the outcome of department's investigation.