double jeopardy

Elizabeth "Libby" Parsons (Judd) holds the belief, subsequently proven correct, that her husband, Nick Parsons (played by Bruce Greenwood), is still alive and had staged his own death for the purpose of falsely convicting her of murder. She serves several years in prison and then emerges bent on finding her husband and son, so as to take her revenge on the former and rescue the latter.

The movie explores the ramifications of a misinterpretation of the legal doctrine of double jeopardy, which is a constitutional right in the United States granted by the Fifth Amendment. Travis Lehman (Lee Jones) advises Libby that she could kill her husband in the middle of Times Square and the police would be powerless to do anything about it because of double jeopardy, because she had already been convicted once for his murder and served time. Both Libby and Lehman repeat this theory later in the movie in order to frighten Nick in the climactic confrontation scene, though it is doubtful that either of them believe it to be accurate legal advice, especially as Lehman is a former law professor.