WHEN WILLIE JONES picked up Joe Theismann and slammed him to the ground in Oakland a couple of weeks ago, it was unnecessary roughness even in the National Football League. Was it also -- or should it have been -- a crime? What if he had gotten Mr. Theismann's shoulders up a little higher and done him severe injury?

The questions are relevant to a hearing held on Capitol Hill earlier this week. Rep. Mottl has a bill pending to make "excessive" violence on the playing fields a federal crime. If this ever becomes law, it will put the federal government, from the FBI through the U.S. attorneys to the justices of the Supreme Court itself, in the business of policing football, hockey, boxing, basketball. Uncle Sam the Referee.

Mr. mottl's idea is terrible -- but it does bring to mind some interesting possibilities. Would unnamed Abscam-like agents bug the huddles? Would assistant U.s. attorneys hire undercover players to ferret out conspiracies aimed at knocking opponents out of the game? Could you ever be sure again, considering all the old KKK and Communist Party infiltrations, that your team was anything but a pack of suited-up FBI informants? Surely judges, perhaps even jurors, would be needing free tickets to RFK Stadium or the Capital Centre to study the action carefully and establish standards of what violence is "excessive."

Of course sports, especially professional sports, need more policing.Their high commands still tolerate much too much violence, and the message too many of their players communicate to their young fans is that anything short of Mayhem goes. But the federal government has enough problems without trying to do something about that.

The job of controlling sports violence belongs to the people who run the games and, if they can't handle it, to the states. After all, if Willie Jones had done the same thing to Joe Theismann on the parking lot instead of on the gridiron, it would have been a crime, and he would have been in trouble with the state of California, not just with Redskins fans.