Not 100% certain what is going on here, but my guess is that a prior judgement issued by the 5th circuit is being re-done based on a change in how the U.S. is interpreting suppressor legality:
Although no one knows exactly what the cause is, this action coincides with recent suppressor deregulation efforts and has been largely embraced as good news by gun rights groups, including Firearms Policy Coalition, which backed this case.
This got appealed to SCOTUS by Peterson - SCOTUS DENIED certiori (hearing the case) today, so the last judgement stands (Peterson guilty of possession of a non-NFA registered silencer):
