(Darby, PA) -- Authorities are still trying to piece together all the facts after a doctor at a Philadelphia-area hospital pulled his own gun on a shooting suspect. Delaware County district attorney Jack Whelan says the suspect was hit three times. The incident happened Thursday afternoon near Mercy-Fitzgerald Hospital. Whelan says the suspect was apparently arguing with a female caseworker in a doctor's office before he shot and killed her. The doctor then returned fire.