Two uniformed New York City Police officers arrived a few minutes later to find that the suspect had put his weapon to the head of a nearby student as the woman he had originally followed hid in another room. The pellet pistol resembled a .44-caliber revolver.
Police say he later removed the weapon from the woman's head and put it to his own.
The officers coaxed the man into dropping the weapon. He was captured and taken to a hospital for a psychiatric evaluation.
Authorities say it was not immediately clear if he was a student.