X-Men: Days of Future Past is released in theaters tomorrow. The film's plot is based off of the 1981 Uncanny X-Men story arc of the same title. In both, an X-Men team member must travel back in time in order to change history to prevent the eventual arrival of an anti-mutant future.
Law and the Multiverse (a legal blog first mentioned here by Matt Cooper) provides an analysis of the legal atmosphere of the comic book's story. Very pertinent to the Days of Future Past story, time travel is also covered in questions of double jeopardy and the statute of limitations.
If you are curious about law in relation to superheroes, you can find more from the authors of Law and the Multiverse in their book The Law of Superheroes. (Someone at the circulation desk can get it out of the display case for you.) If you have further questions about X-Men lore, you can see Matt Watson at the circulation desk.