Chisox,
Probably have to pay the gauranteed portions, unless there is some character clause. The rest they can void just like any other NFL contract as they are not gauranteed.
Its hard to tell where this one will go, my guess is that after the DA collects the evidence, the guy who was assaulted all of a sudden wont want to press charges but will want a civil case.
That way he gets the DA's discovery and investigation for free, and gets the money from the Civil suit. Because why would you care about a guy going to jail for 4 years if you could get money.
