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,

Authorities say a shooter entered UPMC Memorial Hospital's ICU and took staff members hostage before he was killed by police in a shootout.

Cops encountered Archangel-Ortiz holding a female staffer at gunpoint with her hands bound, officials said. The officers engaged Archangel-Ortiz in a firefight, killing him. Archangel-Ortiz wounded two cops and killed a third, who was identified as Andrew Duarte, 30, of the West York Borough Police Department.