Police say they have obtained a warrant for the arrest of Bilal Gay, a juvenile.
He is suspected of fatally shooting 16-year-old Charles Trotman, a spectator watching a basketball game Friday night inside the Martin Luther King Recreation Center in North Philadelphia.
Investigators say the gunfire erupted following an argument and Trotman was the target.
Trotman was shot in the chest and knee. He died at Temple University Hospital.
Police have not said what the argument was about. Dozens of people were inside the rec center at the time of the shooting.