When Ron Martin stood in the Eldorado Parkway median holding aloft a sign warning passing motorists of “Police Ahead,” he insisted his aim was to help officers by getting drivers to slow down before hitting an upcoming speed trap.

Despite Martin’s stated desire to pitch in, his actions led cops in Frisco, Texas — a Dallas suburb — to cuff and arrest him, an incident he recorded on his cell phone last October.

Ron Martin Arrested After Holding Sign Warning of Police Speed Trap Argues First Amendment Rights

Screenshot from Martin’s cell phone captures moment he was arrested. (Image source: WFAA-TV)

As the officer cuffed Martin, he said, “I told you it’s a violation of city ordinance to be a human sign.” Check out the arrest below:

Martin was charged with violating the city’s sign ordinance, which says a person holding a sign has to be on private property; Martin said it doesn’t apply to him because he’s not a business. He’s just started fighting the charge in court this week, reported WFAA-TV in Dallas.

Besides, he added, it’s a free-speech issue.

“Ultimately, we’re trying to do the exact same thing,” Martin noted to WFAA in regard to his actions and police duties. “I just don’t wear a uniform. I’m the same thing as a speed limit sign, just reminding people that there is a limit here.”

Ron Martin Arrested After Holding Sign Warning of Police Speed Trap Argues First Amendment Rights

Image source: WFAA-TV

Is Martin opposed to the speed traps? “Absolutely not,” he told WFAA. “I think it’s absolutely important for officers to be on the streets and enforce laws.”

Martin made his first court appearance on the misdemeanor charge Wednesday; he pleaded not guilty and asked for a February 21 trial date.

Frisco Police indicated that they’ve seen Martin holding signs at least twice before, and this time an officer “observed a couple cars drive by traveling westbound waving at us,” according to Martin’s arrest report, which tipped off cops that Martin may be in the area.

Frisco police said they won’t address the case publicly until court proceedings are completed.

(H/T: Gawker)