A San Francisco homeless couple said they watched Alameda County sheriff’s deputies — who had chased an auto theft suspect into the city — severely beat the defenseless man with batons in an alley, and were then given the wounded man’s cash and jewelry as “hush goodies” by a deputy at the scene.

Jerome Allen and his partner, 31-year-old Haley Harris, said in interviews Tuesday that they were in a tent on Stevenson Street in the city’s Mission District on Nov. 12 when they witnessed the now widely publicized beating of Stanislav Petrov by deputies Luis Santamaria and Paul Wieber that was captured on video and is the subject of multiple investigations.

“They gave me his gold chain, his cigarettes, some change and some other stuff,” Allen, 50, said at a city shelter where he is staying. “They saw my eyes pop out of my head when I saw that chain. They didn’t just decide to give it to me — common sense is it was hush goodies.”

Alameda County sheriff’s officials said the allegation is under investigation, and that a 20-year-veteran deputy implicated in the couple’s account has been placed on paid administrative leave. At a news conference, Sheriff Greg Ahern said his agency had just learned of the account through media reports and Petrov’s attorneys.

While he found the video of the beating “disturbing,” Ahern said, the allegation of theft and bribery was “one of the most horrific things I’ve heard.” He did not identify the deputy but indicated he was not one of the two men who struck Petrov with their batons.

Attorney files claim

The development emerged as attorney Michael Haddad filed a claim Tuesday against Alameda County on behalf of Petrov, 29, the man beaten after he allegedly fled deputies in a half-hour chase in a stolen car from Castro Valley over the Bay Bridge. The deputies said in reports that Petrov had rammed two patrol cars and that they feared he was armed, possibly on drugs and dangerous.

The claim, a precursor to a federal civil rights lawsuit, says deputies not only stole from the bloodied man but also painfully cuffed his fractured hands and used a phone to snap a “trophy photo” of him as he moaned and writhed on the pavement. Ahern said the photo may have been properly taken as evidence but said the assertion would be fully investigated.

The claim alleges misconduct by more than a half dozen deputies who responded to the Mission District, including Santamaria and Wieber.

A lawyer for Santamaria did not immediately return calls Tuesday seeking comment. Attorney William Rapoport, who is representing Wieber, declined to comment, saying he needed more information from authorities. But he said any allegations involving theft or bribery would not involve his client.

Allen told The Chronicle that he and Harris were awake in their tent on the night of the beating when they heard “tires screeching” and what sounded like someone “getting hit.” When they got outside, they said, they saw a man swarmed by two deputies.

“They took him down,” Allen said. “Then they hit him 40 times at least. I yelled, ‘Stop!’ but that didn’t stop them. They acted like they didn’t hear me.”

Harris, in a separate interview, said she figured the necklace offered by a deputy might belong to the bloodied man, but at the time was “sick and scared” and said nothing. “The deputy said to (Allen), ‘Don’t spend it all in one place,’” she said. “I said to Jerome, ‘Maybe they’re trying to buy you off.’”

Haddad said the deputy had told the couple, “I hope you enjoyed the show.”

Allen said he has since been interviewed by the Alameda County sheriff’s internal affairs bureau, which must rule on potential discipline, as well as San Francisco prosecutors, who must decide whether to file criminal charges against the deputies. He said he sold the necklace — which he identified as the one Petrov is seen wearing in a photo on Facebook — for $1,500 on the street.

Allen added that Petrov is a friend and that he was shocked to learn the bloodied man’s identity. “It’s crazy that we just happened to be there when it happened,” he said.

Surveillance camera footage

The deputies’ beating of Petrov came to light because it was captured by a surveillance camera, with the footage released by San Francisco Public Defender Jeff Adachi a day later.

The video footage shows Petrov running from two deputies before being tackled by one of them. According to the claim, Santamaria and Wieber “began viciously beating (Petrov) with steel batons on his head, neck, back, hands, and elsewhere on his body. (Petrov) never resisted, never tried to flee after he had surrendered, and never posed any immediate threat to anyone.”

Haddad wrote that deputies “painfully locked (Petrov’s) crushed hands in handcuffs,” and that one stepped on his head or neck, pressing it into the pavement for more than a minute even as Petrov said, “Please help me.” Haddad said his client suffered not only broken bones in his hands but also head wounds and a concussion.

“This was probably the worst law enforcement beating on video that we’ve seen since Rodney King,” Haddad said at a news conference at his office in Oakland.

He said that even though the camera pointed at the alley was not cutting-edge and did not record continuously, with 10-second pauses in the footage, “We can count approximately 40 or more blows. They’re aiming for Stanislav’s head, which is the use of deadly force, and Stanislav is trying to protect himself with his hands. As a result, his hands were crushed and his head was damaged and he sustained major injuries.”

Haddad said he believes other deputies at the scene “participated in a code of silence concerning the unlawful conduct of fellow law enforcement officers” by authoring false police reports and not activating their body cameras at the time of the incident. “You don’t turn cameras on when you know you’re committing a crime,” he said.

Alameda County sheriff’s officials said Tuesday that Wieber accidentally activated his body camera and that a second video of the beating exists, but they did not release the footage. They said Santamaria and Wieber have been on paid administrative leave since the incident.

San Francisco prosecutors have not decided whether charges are merited.

“As with every case that comes into this office, we must be sure that a thorough investigation has been conducted so that justice is done,” Alex Bastian, an office spokesman, said Tuesday. “At this time, we are unable to comment on it any further.”

Reviewing policies

Ahern said he had reviewed the department’s policies and training since the video emerged. He decided to address gaps in baton training and amend the body camera policy, he said, so that deputies must activate them during all stops. Previously, Ahern said, deputies had the option of using the new devices so that they could experiment and get used to them.

“This event has caused us to look at some gaps and some areas where we need to improve, and we’re going to do that,” he said. “Since the event has occurred, every member of our agency has taken on some type of responsibility to make sure this type of event never happens again.”

The department, Ahern said, is also looking into whether deputies who responded to the scene after the beating acted properly in not stepping in and halting any alleged wrongdoing.

“Those deputies are trained to stop all unlawful actions when they have the authority to do so,” he said. “If somebody knew about that theft and did not report it, they are going to be punished.”

Vivian Ho and Evan Sernoffsky are San Francisco Chronicle staff writers. Email: vho@sfchronicle.com, esernoffsky@sfchronicle.com Twitter: @VivianHo @EvanSernoffsky