Three people on a "cop watch" were arrested while videotaping a traffic stop by an Arlington police officer late Saturday night. The people are part of organizations Texas Cop Block and the Tarrant County Peaceful Streets Project, whose members tape police in a effort to hold them accountable for their actions. Until recently, that mostly meant gathering a small group to drive around Arlington in search of traffic stops (not anything else), parking nearby and pointing a camera. In the past several months, they've done this without incident.

There was a usual script: These people would record, and the cops would do their thing, or the watchers would cause the cops to stop doing what they were doing. At a recent cop watch, I was in the car when we pulled up to one traffic stop. The man was on the ground with had his hands behind his back. As soon as cop-watcher Joseph Tye got out of his car, the two officers let the man go. He got in his truck and drove away, and so did the officers. However, as the group has gotten more publicity, notably a Fox 4 report that got the word out and garnered them their largest attendance yet, the interactions between officers of the Arlington Police Department and the cop watchers have grown heated.

On the past three cop watches before the one Saturday night, several Arlington officers have formed perimeters around each traffic stop the cop watchers attended. But Saturday was when the tension seemed to boil over. As about 20 cop watchers gathered around a traffic stop in a parking lot on Cooper Street, a busy six-lane road, about 10 police cars and more than 20 officers joined them. See also: It's Definitely OK to Film Cops, Texas Judge Rules

The first cop watcher arrested was Joseph Tye. He was standing in the parking lot filming at his usual distance, but apparently that was too close now. As the others filmed, Tye was arrested. Then, three cop watchers -- Jacob Cordova, Kory Watkins, who is also the head of Tarrant County Open Carry, and Watkins' wife -- attempted to walk down the sidewalk to record, which they did normally at traffic stops before this one.

An officer told them to stop, but the watchers continued to walk, getting within about 30 feet of the traffic stop. A squad car drove up behind the three watchers, who were standing in the area where vehicles drive into the parking lot. The car, moving at a slow speed and trying to get in the lot, almost hit Watkins' wife, and Watkins yelled at the officer driving. He and his wife were then arrested.

See also: One Man, One Camera, One Bike: Jose Vela's Dallas Cop Block Aims to Guard the Guardians

All three were out of the city jail by 2 a.m. after being bailed out by the other watchers. They were charged with interfering with police duty and obstructing a highway. Their phones and cameras were confiscated and they haven't got them back yet. They all have court dates.

"They probably did that to kill our cop watch," Cordova said.

Although the Supreme Court has never ruled on recording the police, filming public officials in a public space doing their public duty, as long as you don't interfere with their job, seems to fall under the First Amendment. In July, an Austin judge ruled that a lawsuit brought by Antonio Buehler, who films the Austin police and allegedly was arrested for it, could continue for that very reason.

Ron Pinkston, the president of the Dallas Police Association, told us in July that Dallas officers don't mind being filmed, as long as those filming do not get in the way. Cop Block is a national, decentralized organization. The Peaceful Streets Project was started by Buehler.

Send your story tips to the author, Sky Chadde.