A California cop gave a Marine veteran a concussion for nothing more than filming a traffic stop.

On January 22, Adrian Burrell was at his home in Vallejo, California, when he saw his cousin outside with his hands in the air. The cousin, Michael Walton, was standing next to his motorcycle with his back to a police officer. "He can't hear you. He has his helmet on," Burrell told the officer, according to the account he later gave to KGO. At that point, he says, the cop told him to go back in his house.

Instead, Burrell, who is a filmmaker, opted to record the incident. Even if he hadn't been standing on his own private property, this would be within his rights. In California, citizens can film on-duty police officers as long as they aren't interfering in their work. In this case, Burrell tells The San Francisco Chronicle, he was on his porch—more than 20 feet away from what was going on.

Video taken by Burrell and posted to Facebook yesterday shows what happened next:

"Get back," the officer tells Burrell. "No," he replies. (Burrell notes to the Chronicle that his back was already up against the side of his home.) The officer then walks toward Burrell, holstering his weapon as he does so. "You're interfering with me, my man?" he asks. "You're interfering, you're going to get one from the back of the car."

"That's fine," Burrell responds. The officer starts handcuffing Burrell, and tells him to "stop resisting."

"I'm not resisting you," Burrell says, as the officer threatens to take him down. "Stop fighting or you're going to go on the ground," the cop says.

It's hard to see what happens next, and the camera eventually goes dark. "He handcuffed me and threw me into this wall here," Burrell tells KGO. "Swung my body into that pole there, where I knocked my head. He took me to the car and detained me and told me I was going to jail." Burrell wrote on Facebook that he sufferred a concussion as a result of the officer's actions.

Several seconds later in the video, the officer can indeed be heard saying: "That wasn't very smart, man. Now you get to go to jail."

But Burrell did not end up in jail. Burrell tells the Bay City News he asked the officer to cuff his hands in front of his body, rather behind, due to injuries sustained as a result of his time in the military. "Oh you're a vet? You sure weren't acting like one," Burrell recalls the officer saying, according to the Bay City News.

But he did end up letting Burrell go. Walton, meanwhile, tells the Bay Area News Group that he was given a speeding ticket and also allowed to go on his way.

According to a statement to media outlets from the Vallejo Police Department, Chief Andrew Bidou has "ordered an internal affairs investigation of the incident." In addition to Burrell's video, there is body camera footage of what happened, though it has not been released to the public.

Police have not identified the officer involved, but his nameplate in the video reads "D. McLaughlin." The Chronicle reports that a David McLaughlin was hired by the police department in 2014. That same year, according to the Bay City News, McLaughlin was accused in a civil suit of searching a man's car without cause, then falsifying a police report when nothing illegal was found. The plaintiff eventually died, and the case was dismissed.

Burrell, who is black, suspects his race was a factor in the incident. "I'm not a lawyer," tells the Bay Area News Group. "I'm not a detective. I'm just somebody who went with something and am trying to figure it out, and understand that historically these things happen to people who look like me and in communities like this."

Being able to film police officers is an important part of keeping them accountable. Unfortunately, as Reason has documented on several different occasions, many cops don't feel the same way.