Pennsylvania State Police are looking into the shooting death of a 27-year old man at a Summit Township trailer park. According to police, it happened shortly 10pm Monday at the Popp's Mobile Home Park off Route-97. Police tell us it started as an argument between 27-year old William Haggerty and his 28-year old girlfriend Christine Mae Allen. At some point, police say a gun was introduced into the mix. Police say there was a fight over a gun and the weapon went off, killing Haggerty. State troopers spent much of the night gathering evidence at the scene and questioning Allen, but so far no charges. Watch 12News and SEE News for the latest developments.