From a New York Times obit by Robert D. McFadden headlined “William Klein, Who Photographed the Energy of City Life, Dies at 96”:

Exterior. Daylight. Two boys in a doorway. The older, 11 or 12, holds a revolver aimed at your left eye. He is snarling, ready to kill you. The younger, maybe 8, has the face of an angel. It is a grainy black-and-white photograph, staged circa 1954, titled “Gun 1, New York.”