The gunman who held intensive care unit staff hostage at UPMC Memorial Hospital in Pennsylvania before killing a police officer and injuring five other people Saturday believed that more could have been done to save his wife,

A man who took hostages in a Pennsylvania hospital during a shooting that killed a police officer and wounded five other people highlights the rising violence against U.S. healthcare workers and the challenge of protecting them.

Injured, 2 Dead in Pennsylvania Hospital Shooting, UPMC Memorial Hospital, Diogenes Archangel-Ortiz, Andrew Duarte

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.

The attacker who killed a police officer and took three people hostage at a Pennsylvania hospital was identified Sunday, as authorities said he visited the hospital before. Diogenes Archangel-Ortiz, 49,

The suspect, Diogenes Archangel Ortiz, entered the hospital with handgun and zip ties Saturday morning and took several staff members hostage, state officials said.