Philadelphia's police commissioner says he's surprised the gunman who wounded six officers surrendered after he barricaded himself in a home for hours.
Richard Ross says the gunman mentioned he had an extensive criminal history as he tried to negotiate his surrender on a cellphone.
The commissioner says he does not believe the gunman knew two police officers were trapped upstairs in the home along with three civilians.
He says the tear gas ultimately caused the gunman to come out early Thursday. The gunman was taken to a hospital for evaluation and then placed into custody.
His name has not been released.
The shooting started Wednesday when gunfire erupted in the home as officers were serving a narcotics warrant.
The six officers who were shot have been released from hospitals.