On July 28, 1931, Coll allegedly participated in a kidnapping attempt that resulted in the shooting death of a child. Coll's target was bootlegger Joseph Rao, a Schultz underling who was lounging in front of a social club. Several children were playing outside an apartment house. A large touring car pulled up to the curb, and several men pointed shotguns and submachine guns towards Rao and started shooting. Rao threw himself to the sidewalk, and four young children were wounded in the attack. One of them, five-year-old Michael Vengalli, later died at Beth David Hospital. After the Vengalli killing, New York City Mayor Jimmy Walker dubbed Coll a "mad dog".