Is it a crime to warn drivers of police speed traps? In Grain Valley, the police seem to think so

Jerry Jarman was driving through Grain Valley at 9:25 a.m. on August 24, 2014, when he saw that police there had set up a speed trap.

Jarman wanted drivers to slow down, so he sent out the universal warning sign by flashing his headlights at oncoming traffic. For this public service, Jarman was pulled over and issued a ticket.

Grain Valley’s city code makes it illegal for anyone to warn others of speed traps. The city seems to prefer that warnings about driving at safe speeds be left to its police force — after a cop stops someone and issues a fine.

Jarman’s ticket was accompanied with a court date. Jarman hired a lawyer and got his charge dismissed. But he won’t stop there.

The American Civil Liberties Union filed a lawsuit against Grain Valley on behalf of Jarman. He thinks Grain Valley police could stop him again if he warned drivers in the future.

The lawsuit, filed in federal court in Kansas City on Wednesday, seeks to gut Grain Valley’s prohibition against headlight-flashing. The law is probably on the ACLU’s side.

The ACLU filed a similar lawsuit last year when Ellisville, Missouri, police stopped a man there for doing exactly as Jarman did. Like Jarman’s, Michael Elli’s ticket was dismissed, but only after he appeared for his court date and told a judge that he didn’t think he’d broken the law and wouldn’t plead guilty. The municipal judge didn’t like hearing that and asked Elli whether he understood the meaning of “obstruction of justice.”

It is illegal to interfere with a police investigation (speed traps could be viewed as an investigation), but it’s not against the law to tell someone else to obey the law.

Grain Valley officials were not immediately available to comment said through a spokeswoman that it had no comment for now because the case is in pending litigation, but would make a statement in the coming days.