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

The man who authorities say entered a Pennsylvania hospital with zip ties and a pistol over the weekend had recent contact with the hospital's intensive care unit, where he took staff members hostage and was killed in a shootout that left a police officer dead and others injured.