A California Highway Patrol officer straddles a woman near an exit ramp on Interstate 10 in Los Angeles. He is punching her in the face -- pummeling her like a boxer while she writhes on her back, trying to fend off the blows.
Chances are we would have never known anything about this July 1 incident, which has now been all over the news, were it not for the fact that a man named David Diaz happened to be driving by moments earlier. Diaz, who was in a car with three other people, stopped when he saw a CHP officer attempting to arrest a woman walking on the freeway. He turned on his cellphone and captured the officer as he started punching the woman in full view of passers-by. Diaz uploaded the video to YouTube. It went viral.
You can't watch the clip of the beating -- the relentlessness of the blows -- and not be sickened.
"This is a grown man punching to the point where she could have died out there," Diaz later told KNBC 4.
Oakland attorney John Burris is a member of the legal team representing Marlene Pinnock, 51, who has filed a civil rights lawsuit against the CHP. Burris, who represented Rodney King and Oscar Grant's family in civil suits where citizen video of police actions played a major role, said Diaz's cellphone video will be a key piece of evidence.
Regardless of what may have occurred in the moments before the beating, Burris says, "The video shows that he (the officer) was throwing punch after punch at her while she was in a subservient position."
CHP Commissioner Joe Farrow has said he was "deeply concerned" by the video and promised a prompt investigation. CHP officials have said that the video only tells part of the story.
According to the CHP, Pinnock, a homeless woman who appeared disoriented, had been wandering in and out of lanes of traffic on the freeway. She was posing a danger to herself and others. At least nine concerned motorists had called 911 to report her. The CHP said Pinnock became combative and uncooperative when the officer tried to arrest her.
While that may well be true, it will still be hard for the CHP to justify the vicious beating that was captured on video.
In fact, the video is exhibit A for why citizens should have a right to videotape the police going about their official duties in public places.
Whether it's a good Samaritan looking out for another's welfare or a simple voyeur, increasing numbers of people are using their cellphones to videotape the police. Citizen video can provide valuable evidence in investigations of possible police abuse.
Last Thursday, when police officers in Staten Island, New York, placed Eric Garner in a choke hold, there were people nearby recording with cellphones. The police had stopped to question Garner, 43, about the fairly minor crime of selling loose cigarettes. He ended up dead after being placed in a choke hold by two of the officers.
A seven-minute video posted to Facebook shows Garner lying handcuffed on the ground while police wait for the ambulance to arrive.
People who try to record police officers do so at their own risk. There have been instances of police around the country threatening and arresting those who try to record them. One website, Photography is not a Crime, is even dedicated to reporting such incidents.
There have been a number of court rulings establishing that citizens have a First Amendment right to record police officers in public places. However, that won't protect you from getting arrested for trying to do so.
"An officer might not understand the law or say, 'I don't care I'm going to arrest you anyway,' " says Clay Calvert, a professor of mass communication at the University of Florida who specializes in First Amendment issues.
"Then that person is left to fight it out in court, which can take a significant amount of time and money."
Given the value of citizen-produced video in helping to hold police officers accountable, the right to videotape the police is worth fighting for.
Tammerlin Drummond is a columnist for the Bay Area News Group. Her column runs Tuesday and Sunday. Contact her at email@example.com or follow her at Twitter.com/tammerlin.