As Donahue and Halloran drove out of the parking lot, Weeks signaled Bulger by stating, "The balloon is in the air" over a walkie-talkie. Bulger drove up with another man armed with a silenced MAC-10; Bulger himself carried a .30 Carbine. Bulger and the other gunman, both disguised, opened fire and sprayed Halloran and Donahue's car with bullets. Donahue was shot in the head and killed instantly. Halloran lived long enough to identify his attacker as James Flynn, a Winter Hill associate, who was later tried and acquitted. Flynn remained the prime suspect until 1999, when Weeks agreed to cooperate with investigators and identified Bulger as one of the shooters. Flemmi has identified the second shooter as Mulvey, who has denied the allegation and has yet to be charged.