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.

Authorities described the shooting of a gunman who opened fire at a Pennsylvania hospital as “absolutely justified, beyond any and all doubt.”

Violence at hospitals is on the rise, often in emergency departments but also maternity wards and intensive care units, hospital security consultant Dick Sem said.