Gamble is an L.A.P.D. officer and a close friend of Jim Street, another member of the L.A.P.D. unit who Gamble serves with. Gamble accompanies Street and his S.W.A.T. team to a bank that has been taken over by a gang of robbers, but Gamble disobeys orders not to fire on them and ends up wounding a hostage in the process. He and Street are then demoted by the commander of the L.A.P.D. Metropolitan Division, Captain Fuller, and following an intense argument between Gamble and Fuller, Gamble quits and leaves. Street, however, is inserted into Sgt. Hondo's S.W.A.T. unit.
A while later, Street finds Gamble in a bar and they have a brief but awkward confrontation. Street is unaware that Gamble is plotting to free French drug lord Alex Montel from police custody, as Montel had made a public announcement that he would give $100 million to whoever is able to free him.
Gamble uses a high-powered rifle to shoot down a helicopter that was meant to take Montel into federal custody, and he later confronts Street and his S.W.A.T. team as they are driving Montel away in an SUV. Gamble rescues Montel with the help of another traitorous L.A.P.D. officer named T.J. McCabe and they escape onto a train with Street and Hondo in hot pursuit. Street and Hondo tries to shoot Gamble but the train speeds away before he can take a shot at him and Gamble gives the middle finger gesture to the two.
Gamble, Montel and T.J. venture into the sewers to avoid detection, but S.W.A.T. members manage to follow them. Gamble and his team then arrive at a bridge where a plane is due to land to take Montel out of the United States. Street and the other S.W.A.T. members notice a low flying plane and decide to approach it just as Gamble and Montel are about to leave. However, before the plane can take off, Street's team ram their car into it and cause it to crash, initiating a gun battle between them and Gamble's henchman Travis. As the other S.W.A.T. members take care of Montel and T.J., Street chases his former friend off the bridge and onto a series of railway lines. Gamble fights Street but Street accidentally kills him by knocking him into the path of a slow moving freight train, where its wheels decapitate him.