McLaughlin first began operating as a loan shark and enforcer for the Angiulo Brothers of the North End, Boston. After the Irish gangs decided to break away from Italian control, Bernie and his brothers Edward McLaughlin and George McLaughlin took over the rackets in and around Charlestown, Massachusetts, forming their own crew which at it's peak was said to be made up of 40 to 50 members. They soon built a reputation as a fearsome crew, and carried out contract killings for gangsters all over New England, including the Patriarca crime family and the Winter Hill Gang.