Conduct Unbecoming is a military courtroom drama. Commander Mike DeMarco, the Navy’s most successful criminal defense attorney, is fed up with the bureaucracy and contemplates retirement. However, he takes one last case for a young sailor, Joshua Miller, who is charged with the murder of a marine war hero and is facing the death penalty. The evidence is largely circumstantial, yet Miller, for some reason, refuses to cooperate in his own defense. DeMarco presses on believing he can win an acquittal without his client’s help.
Shortly before trial Miller has a change of heart. He tells DeMarco a bizarre story about falling in love with a beautiful, rich college student who unexpectedly called his barracks. He and his “girlfriend” talk for weeks but, despite several attempts, never meet. Miller becomes frustrated and they break up. The next morning she calls alleging she was raped by three marines but refuses to give Miller more information. Shortly thereafter, Miller while in the cafeteria notices a marine named Williams giving him a “funny look.” Initially the girlfriend denies Williams’s involvement but later says he was a party to the crime. Miller impersonates an NCIS agent and on New Year’s Day tries to obtain a confession from Williams, who denies knowing the girl or being involved in a rape.
Miller now wants to take the stand and tell his story. DeMarco tries to convince him to remain silent and allow him to do his job. When Miller refuses, DeMarco knows the only way to save his clients life is to find this girl and get to the truth about what really happened.