Robinson said most people prefer a more informal process that often doesn't show up in official statistics, like having a police supervisor hear the complaint and talk to the officer.
The panel has recommended that local agencies allow anonymous and third-party complaints to shield victims from retaliation, while making it easier to file complaints, including by providing materials in many languages.
There should be follow-ups so complainants don't feel they're being ignored, Guerrero said, and civilian oversight panels with "teeth in them" should oversee complaint investigations.
Plumas County Sheriff's Deputy Ed Obayashi, an expert on use-of-force policies who teaches other law enforcement personnel around the state, said the racial numbers don't reflect reality, but he discounted any nefarious intent.
In Southern California, the San Diego County Sheriff's Department, where Obayashi used to work, reported just one racial profiling complaint in 2017, while the Riverside County Sheriff's Department had seven. About 3.34 million people live in San Diego County, while the population of Riverside County, which includes the cities of Riverside and Palm Springs, is around 2.42 million.
The Los Angeles County Sheriff's Department, the United States' largest sheriff's agency, recorded 31. "There's no way," Obayashi said. "People who see this report are going to say, 'They're covering this up.'"
He and others blamed conservative reporting policies that leave out informal complaints, coupled with "complaint fatigue" by people who are too frightened to complain or believe they'll be ignored.
Proving a complaint is even tougher, he said.
"To sustain a complaint would require the officer to say, 'I stopped that motorist because he was black or Hispanic.' And what officer is going to admit to that?" Obayashi said.
The 7,400-officer California Highway Patrol reported just 24 profiling complaints from nearly 4 million contacts with the public. None was substantiated by the department, which board member Warren Stanley, the CHP's first black commissioner, said shows the professionalism of the agency's personnel.