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,

A gunman and a responding officer were killed after shots were fired Saturday at a hospital in central Pennsylvania.

A memorial is growing as a Pennsylvania community mourns the loss of a police officer on Saturday. The officer was killed in the line of duty when a gunman opened fire inside the UPMC York Memorial Hospital.