Detective J.J. McVea of the Charles street station, who arrested the boys, says that the robbery of the safe was a remarkable one and showed no trace of amateurism. It was committed by four boys. Besides Lyons and Murphy, he says, there were in it Albert Moquin, 14 years old, of 68 West Third street, and one whom Lyons calls “Oscar the Wop,” or “Oscar the Dago.”
Source: wiktionary