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

Andrew Duarte was texting his girlfriend before he got called to the York County UPMC hospital. Then she started seeing reports on Facebook of an active shooter.

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.