Advocates for the disabled on Thursday urged the state Department of Justice to take over the investigation and prosecution of a former Sonoma Developmental Center employee who is alleged to have used a stun gun on 11 patients.

In a letter to Attorney General Kamala Harris, Greg deGiere, a spokesman for The Arc and United Cerebral Palsy, accused local authorities of failing to conduct a thorough investigation into claims that caregiver Archie Millora, 38, used the weapon on patients last fall.

DeGiere said the Sonoma County Sheriff's Office and the institution's own police force, the Office of Protective Services, were slow to respond, while prosecutors allowed Millora to plead to a misdemeanor weapons charge carrying a penalty "that would make a slap on the wrist look harsh."

Afterward, the Sheriff's Office and Office of Protective Services pointed fingers at each other, he said. And the District Attorney's Office promised to revisit the case only after it was reported by the media, he said.

"The bottom line is, this is a case of serial torture and no one has been arrested on these charges," DeGiere said in a phone interview Thursday. "We're asking the attorney general to take over."

Sheriff Steve Freitas said the Office of Protective Services informed his detectives they had a suspect but declined any help from the Sheriff's Office.

"They never asked us for any investigative help. If they did we would have given it to them," Freitas said. "We generally don't go in and force our investigative unit on other law enforcement agencies."

Spencer Brady, chief deputy district attorney, said only that his office was "continuing to review the case both from a legal and factual standpoint."

"The door here is open to additional information and further review," Brady said.

The institution received the allegations about Millora on Sept. 26 from an anonymous tipster, according to a report by California Watch, part of the Berkeley-based Center for Investigative Reporting.

The caller accused Millora, who was later fired, of using a stun gun on men in a unit for the severely disabled.

Doctors confirmed the injuries and officers found a stun gun in Millora's car, but he wasn't immediately charged or arrested.

Instead, the case was handled as an administrative matter.

The Office of Protective Services delayed interviewing witnesses, including Millora, and downplayed the seriousness of the case, California Watch reported.

For instance, the state agency didn't immediately tell the Sheriff's Office it had confirmed cases of abuse. The sheriff has jurisdiction over Sonoma Developmental Center.

The director of the state Department of Developmental Services said the Sheriff's Office decided not to take over. But Freitas said the Office of Protective Services never asked for help.

"The thing we got from them from Day One is they had this case," Freitas said. "They had a suspect and didn't need our help."

In the end, prosecutors reviewed reports from internal police, which determined the stun gun found in Millora's car wasn't used on the patients.

Millora wasn't charged with assault. He instead pleaded no contest to having a loaded Glock pistol in his car. He received home confinement and probation.

DeGiere expressed concern that Millora may be free to take other jobs that put him in contact with disabled people.