Petrov faces felony charges for ramming a squad car and injuring a deputy, then leading a high-speed chase to San Francisco. Alameda County Sheriff's Sgt. Ray Kelly said Petrov is also being held on suspicion of having a loaded firearm in the stolen vehicle he was driving, possession of methamphetamine and multiple hit-and-runs.
His arrest was captured on video provided to the San Francisco Public Defender's Office, which published it Friday.
Two deputies who caught up to Petrov near the corner of Stevenson Street and Clinton Park in San Francisco's Mission District are facing an internal investigation.
One is shown tackling Petrov after he rammed into a parked car and ran from the vehicle. Then he and his partner are seen beating Petrov on the head, arms, legs and torso with batons. The beating went on for an indeterminate amount of time -- the video skips approximately every 10 seconds -- and continued even after other officers arrived on the scene.
Petrov is heard crying out in pain at several points in the recording.
"The video raises concern, and we opened the investigation," Kelly said, adding that the department is considering whether to place the deputies on administrative leave or reassign them while the probe plays out. He said the incident also raises a jurisdictional issue because it happened in San Francisco.
"There’s a lot of things we’re doing internally right now trying to deal with this," he said.
The department is also seeking additional video of the incident. Kelly confirmed that Alameda County sheriff's deputies are equipped with body cameras, but he was unsure if the arrest was recorded by the devices. The department's policy does not require deputies to turn them on.
"I guess you’d call it discretionary on behalf of the officer," he said, "discretionary but highly encouraged."
The deputies have not returned to work since the press brought the video to the attention of the department, Kelly said. The deputies, both "tenured" and having served in the department for several years, have not been publicly identified.
Kelly said the department will release their names at some point, but right now there is a concern for their safety.
"If you look on social media, there’s a lot of threats that have been made against them -- pretty vulgar threats," he said. "We have to worry about their safety, in addition to Mr. Petrov in the hospital, too. We don't want people showing up there, protesters showing up there and causing a whole bunch of problems."
Public Defender Woods said Saturday that he spent much of the day trying to locate Petrov, but was unsuccessful. He called the force depicted in the video "insane."
"I was shocked, outraged and disgusted," he said. "I counted over 30 baton strikes. I'm not sure what facts would justify that sort of brutal beating."
Woods said he is trying to identify the deputies because the incident will likely impact other cases they've handled. He said the force they used raises "an issue of credibility."
"I don't plan on letting this go at all," he said. "I think it's just disgusting. The guy is clearly about to give up. ... You hear smack, smack, smack. He's yelling 'Stop!' It's just terrible."
Reached by phone Saturday, Olga Petrova said the incident had shaken her trust in law enforcement.
"It’s gone," she said. "Those people, I want them. I want to have a lawsuit. I want them to pay not from American taxpayers. I want them to pay from their pension funds. I want them to pay for how they tried to kill him and what they have done to me."
Petrova said she emigrated with her son, who she calls "Stas," from Ukraine to San Francisco 18 years ago. She said her son, now 29, has led a difficult life -- diagnosed with multiple mental disorders, including post-traumatic stress disorder and depression. She said he had suffered several concussions in the past.
"He was diagnosed in his early childhood," she said. "He was born a blue baby and he was fighting for his development."
Petrova said Petrov was prescribed Ritalin as a child, which she believes led him to use methamphetamines as an adult.
"He is my life," Petrova said. "When we have poor, misfortunate, sick kids, we probably feel more compassion."
Her recent contact with her son has been intermittent, she said, and the last time she saw him was about two months ago after she'd been searching for a while.
"I kissed him promptly and I asked him, 'Stas, please be careful, I don’t know what is going on with you. Please be careful, I am exhausted, I can’t stand these sleepless nights,' " she said.
Petrova said her son is often "unpredictable," and he struggles with finishing complicated tasks. She again lost touch with him and was shocked when she saw him being tackled and beaten on television.
"People who know him tell me, 'He loves you to death,' " Petrova said. "It’s a very painful kind of love."