A 32-year-old man was shot and killed in his West Philadelphia apartment Monday night while trying to stop a robbery of his roommate and friend, police said.

The victim, Barry Jones, lived in the second-floor apartment on the 5400 block of Girard Avenue with a female friend and her relative, Homicide Sgt. Bob Kuhlmeier said Tuesday. 

The friend, 36, had "arranged a date" with a man and invited him to the apartment, Kuhlmeier said. But when the man came into the apartment about 10 p.m., he announced a robbery, then shot Jones at least once in the head after Jones tried to stop the robbery, Kuhlmeier said.

After shooting Jones, the assailant robbed the woman of cash and her cellphone before fleeing. As of late Tuesday afternoon, the gunman had not been arrested or identified, the sergeant said.

Kuhlmeier said detectives are still trying to determine if the woman had previously met the man and were trying to determine his identity.

Jones, who was shot in the head, was taken to Penn Presbyterian Medical Center, where he was pronounced dead at 10:46 p.m. Monday.

Police on Tuesday also released the name of a man who was shot dead Monday afternoon on the 2200 block of Cecil B. Moore Avenue in North Philadelphia.

Dimere Allen, 19, was found lying outside about 3:45 p.m. with a gunshot wound to his head. Allen, who lived a couple of blocks away on the 2300 block of Oxford Street in North Philly, was taken by police to Hahnemann University Hospital, where he was pronounced dead shortly afterward. Police said the motive of that shooting remained unknown. No arrest has been made.