After he had finished speaking and handing out the notes to his staffers, Dwyer then produced a manila envelope with a Model 19 .357 Magnum revolver in it. When the crowd in the room saw what Dwyer had pulled out of the envelope, the mood changed immediately from one of waiting to see whether he would resign his office to one of panic as nobody knew what he was planning to do with the gun. People gasped, and Dwyer backed up against the wall, holding the weapon close to his body. Dwyer calmly stated to his audience, "Please, please leave the room if this will ... if this will affect you."

Some people in the room left to call for help. Among those who stayed, some pleaded with Dwyer to surrender the gun while others tried to approach him and seize the weapon. Dwyer warned against either action, exclaiming in his final words, "Don't, don't, don't, this will hurt someone." Just seconds later, Dwyer quickly fired one shot through the roof of his mouth and into his brain, and collapsed to the floor, dead. Five news cameras recorded the events. One of the cameras remained focused on Dwyer and captured close-up footage of the aftermath of the shooting; as his body slumped, blood streamed from the exit wound in the back of his head as well as from his nostrils and mouth. He died instantly from the gunshot shortly before 11:00 a.m. EST but was not pronounced dead until 11:31 a.m. An aide later stated that Dwyer's corneas were made available for transplant per his organ donation wishes, but that no other organs were usable by the time his body reached a hospital.