A gunman who held medical staff hostage before killing a police officer and wounding five others at a hospital in south-central Pennsylvania Saturday is believed to have visited the facility in the days leading up to the incident,

Investigators are trying to determine why a man targeted a Pennsylvania hospital, taking workers inside the intensive care unit hostage and holding one staff member at gunpoint as her hands were bound

An officer was killed, and six others were injured after a man armed with a pistol and zip ties entered into a Pennsylvania hospital's intensive care unit Saturday afternoon. Police were called to UPMC Memorial Hospital on Innovation Drive and Roosevelt Avenue in York County,