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 by zip ties.

Authorities said the suspect held hospital workers hostage, opened fire and shot people including a doctor, a nurse, a custodian, and 3 officers.

HARRISBURG, Pa. (AP) — A funeral service will be held later this week for a Pennsylvania police officer shot and killed while responding to a hospital intensive care unit where authorities said a gunman had shot three hospital employees and taken staff members hostage last weekend.

Authorities say a gunman entered a Pennsylvania hospital’s intensive care unit and took staff members hostage before he was killed by police.

A man who took hostages at UPMC hospital during a shooting that killed a police officer and wounded five others highlights the rising violence against U.S. healthcare workers.