DUBLIN — Alameda County Sheriff Gregory Ahern vowed Tuesday that deputies involved in the November beating of a suspect in a San Francisco alley would be held accountable for their actions and laid out a series of reforms — including making body camera use mandatory — stemming from the incident.

“Every baton strike they will have to answer for,” the sheriff said.

The sheriff’s statements came on the same day that Stanislav Petrov’s attorneys, Michael Haddad and Julie Sherwin, filed a claim against the county and detailed a barrage of allegations related to brutality, bribery and cover-up in the incident.

Sherwin said that Petrov was struck at least 40 times with batons on his head and neck area, causing him to spend 12 days in the hospital and suffer permanent damage to his hands.

“This was probably the worst law enforcement beating on video that we’ve seen since Rodney King,” Haddad said.

In the claim, the attorneys alleged that deputies took a “trophy photo” with a bloody and battered Petrov and offered up his gold chain and cash to homeless onlookers in exchange for keeping quiet about the beating.

“Oh God. … Somebody, please help me,” Petrov pleaded during the assault, according to the document.

Ahern acknowledged the disturbing nature of the incident, which was captured on a surveillance camera in a Mission District alley.

The beating occurred after Petrov led deputies on a high-speed chase from Castro Valley across the Bay Bridge in a stolen white Mercedes-Benz. Haddad said the Mercedes had been leased to Petrov, but he had failed to return it to the dealership when required.

Only one of the 11 deputies on the scene of the incident had turned on their body camera — and that was by accident.

Ahern said that fact, as well as a comprehensive study done by the Sheriff’s Office, was enough to no longer make it optional for deputies to turn on their cameras.

He added that, in response to the incident, he’d also reviewed the office’s use-of-force policy, had all deputies sign a law enforcement code of ethics and was reviewing the recruit-training process.

Haddad said it’s not the first time his firm has handled a police brutality case involving the Sheriff’s Office, which he thinks has issues with excessive force.

“Clearly, this is a department that has some problems with its culture,” Haddad said. “When the culture of a law enforcement agency goes bad, it’s usually bad all the way to the top.”

The baton-wielding deputies, Luis Santamaria and Paul Wieber, have been on paid leave for months, and just last week, the Sheriff’s Office placed a third deputy, with 20 years on the force, on leave.

Attorneys for Santamaria and Wieber did not immediately return calls.

Ahern said that investigators believe the third deputy, whom he declined to name, was the one accused of trying to bribe witnesses.

The bribery allegations were brought to the attention of the Sheriff’s Office when the homeless individuals spoke to the media, according to Ahern.

Ahern also responded to allegations from Haddad and Sherwin that reports drafted by the deputies four days after the incident clashed with protocol that mandated supplemental reports be written on the day an incident occurred.

The delay was caused because investigators for the Sheriff’s Office asked for more extensive reports due to the nature of force used, according to Ahern.

Ahern said the Sheriff’s Office will wait to act on its investigation until the San Francisco District Attorney’s Office decides whether to purse criminal charges.

Max Szabo, a spokesman for San Francisco District Attorney George Gascon, said the incident is still under investigation.

Staff writer David DeBolt contributed to this report. Contact Dan Lawton at 408-921-8695. Follow him at Twitter.com/dlawton.