An off-duty NYPD police officer shot a 19-year-old from Queens in the St. James Park last night after the teen fired a gun into the park.Police say Javon Julien was firing a gun into the St. James Park near Crescent Avenue when two off-duty officers confronted him. They say the teen fled, firing shots at the officers. Then, one of the officers fired back, hitting Julien in the torso.Julien was taken to the hospital and is in stable condition.Police recovered a loaded .25-caliber handgun from Julien. He was arrested and charged with attempted aggravated murder, attempted assault and criminal possession of a weapon.