The double jeopardy clause, included in the Fifth Amendment of the Constitution, provides protection against being prosecuted again for the same offense after being acquitted, convicted, and/or punished for the same offense.
A gruesome triple homicide is committed in a quite neighborhood in 1985, near Fort Bragg, NC. A suspect is soon identified, and Timothy Hennis is convicted of the crimes in 1986, being sentenced to death. An appeal in 1989 overturns the verdict, and Tim is a free man.
So how is the same man tried for the same crimes 20 years later? Did he do it? If he did, what about the physical evidence that doesn't match? Mr. X? And if he is innocent, as he claims, why did so many people identify him at the murder scene? This case is studied in law schools all over the US.
Innocent to the Civilians, Guilty to the Army.