A Northern California sheriff’s office has stripped 47 deputies — 10% of the force — of their guns and arrest powers because they failed psychological exams, it was reported Monday.

It was “horrible” to have to relieve the deputies of their duties, Alameda County Sheriff’s spokesman Lt. Ray Kelly told KTVU-TV.

The station obtained a copy of a letter notifying the deputies of their change of status last Friday. The deputies will still receive their pay and benefits.

The move came after the Sheriff’s Office conducted an internal audit of deputies’ psychological examinations from January 2016 to the present.

The letter from Sheriff Gregory Ahern notified a deputy — whose name was blacked out in the copy — that the deputy had been graded “D. Not Suited” in a psychological evaluation and under state law couldn’t serve as a peace officer.

The letter said the Sheriff’s Office had previously been operating under incorrect advice received several years ago from the California Commission on Peace Officer Standards and Training, which said it could hire candidates who received such a rating.

Ahern said the deputy can be hired if a second examination declares him or her “suitable” and the office intends to schedule an appointment for such an exam.

“Our intention is to resolve this issue as quickly as possible,” Ahern wrote. “We also intend to have you return to full duty status once you obtain a ‘Suitable’ finding.”

Kelly said he hoped that the retests would occur in the next two months. The tests will be conducted by a psychologist who doesn’t work for the sheriff, he said.

Kelly said the audit followed the arrest earlier this month of former Deputy Devin Williams Jr., 24. He is charged with shooting and killed a couple in their Dublin, Calif. home on Sept. 7.

His mother, Anitra Williams, told KTVU-TV that her son had been in a romantic relationship with Maria Tran and he believed she was unmarried.

The station said four sources said Williams had failed his psychological exam, although Kelly previously said Williams, who was hired in September 2021, had passed all psychological tests.

The Ella Baker Center for Human Rights, an Oakland nonprofit that deals with race and criminal justice issues, accused the Sheriff’s Office of previously turning a “blind eye” to the problem of unsuited deputies.

“This further highlights the egregious levels of dysfunction and corruption that have plagued the sheriff’s office for years,” the center’s organizing director Jose Bernal, said in a statement.

Kelly said the department has been under “enormous pressure” to hire more deputies and it was hard to find people for the tough job.

“I know that people are going to assume that all these deputies are killers,” Kelly said. “But that’s not true. This test tries to find out if you are psychologically suitable for the job, to handle all the horrible things we see. At the age of 22, sometimes you’re not. I know this isn’t good. But it’s not as bad as it sounds.”