After his release, Bulger worked as a janitor and construction worker before becoming a bookmaker and loan shark under mobster Donald Killeen, whose gang, The Killeens, had dominated South Boston for over twenty years. The Killeens were led by three brothers—Donnie, Kenny and Eddie—along with Billy O'Sullivan and Jack Curran. Their base was the Transit Cafe in South Boston, which later became Whitey's Triple O's. In 1971, Killeen's younger brother Kenny allegedly shot and mauled Michael "Mickey" Dwyer, a member of the rival Mullen Gang, during a brawl at the Transit Cafe. A gang war resulted, leading to a string of killings throughout Boston and the surrounding suburbs. The Killeens quickly found themselves outgunned and outmaneuvered by the younger Mullens. It was during the war that Bulger set out to commit what Weeks describes as his first murder, of Mullen member Paul McGonagle. However, Bulger instead executed McGonagle's law-abiding brother Donald in a case of mistaken identity.