Andrea Yates, the woman who made headlines for drowning her five children so they wouldn't grow up to become evil, who was convicted of murder, whose conviction was overturned, and who was given a new trial, was found not guilty of murder.
This does not mean that she is innocent. This means that she is not guilty. The reason given is insanity. The insanity defense is basically a last-ditch defense offered up by defense attorneys, and usually isn't used unless there's no other way to go. What happens is, the case is such a slam-dunk for the prosecution that there's no real way to defend your client, and she or he will go to jail, basically for the rest of his or her life, if not be subjected to capital punishment. Insanity, however, sends the defendant to an institution. These people have the glimmer of hope that someday they might recover from their insanity, and then be released back into the general populace. However, this is an extremely rare situation, where the hospital determines these people are sane enough to leave the hospital.
Andrea Yates won, but she won in name only.