LANCASTER – Police arrested a J.P. McCaskey High School senior after officials received information that the student brought a gun to school. 18-year-old Darnell Greene of Lancaster Township was found to be in possession of a .22 caliber semi-automatic handgun. The handgun was not loaded and Greene did not possess any ammunition for the weapon. Greene was also found to be in possession of a small amount of marijuana. Greene is being charged with possession of a weapon on school property, carrying a firearm without a license, and possession of marijuana.