The Los Angeles County Board of Supervisors Tuesday approved District Attorney George Gascón’s request to appoint a special prosecutor to assist with cases of alleged police misconduct.

The supervisors offered no comment before voting on the matter.

Gascón plans to appoint former federal prosecutor Lawrence Middleton for a four-year term at a cost of no more than $1.5 million annually, according to his letter to the board.

While campaigning, Gascón promised to reevaluate fatal officer-involved shooting cases—including one in Long Beach—that his predecessor, Jackie Lacey, declined for prosecution.

In his letter, Gascón said the appointment is needed “to promote public confidence in the decision-making process and the outcome of any such investigations” and would be “a positive step in rebuilding relationships in our community.”

Middleton has more than 30 years of experience as a trial lawyer and led several divisions or sections of the U.S. Attorney’s Office for the Central District of California, which consists of Los Angeles, Orange, Riverside, San Bernardino, Ventura, Santa Barbara and San Luis Obispo counties.

Middleton was part of the team of lawyers who prosecuted the federal case against four Los Angeles Police Department officers charged in the 1991 Rodney King beating. All four were acquitted of state charges of excessive force; two of the four were subsequently convicted of federal civil rights violations.

Though Gascón did not prosecute any officer-involved shootings during his nearly nine years as San Francisco’s district attorney, he has told critics that none of those cases involved unarmed suspects.

While campaigning against Lacey, Gascón promised to review several high-profile fatal shootings involving multiple police agencies, including the death of Hector Morejon, 19, who was shot in the back by a Long Beach police officer investigating a report of trespassing and vandalism in April 2015.

The move to appoint a special prosecutor comes as Gascón defends his moves to push through new policies that include no longer pursuing death sentences, not prosecuting juveniles as adults and doing away with most sentencing enhancements.

Though praised by many criminal justice advocates, the changes have also prompted condemnation and legal action from the union that represents county prosecutors and some victims’ rights groups who say Gascón is undermining public safety.

An effort to recall Gascón has garnered the backing of former District Attorney Steve Cooley, former Los Angeles City Councilman Dennis Zine and former county Supervisor Michael Antonovich.

“No confidence” votes have been approved by city councils in Beverly Hills and Santa Clarita.

Defending his priorities in a news conference last week reviewing his first 100 days in office, Gascón said his new policies were “based on data and science that will enhance the safety for our community while reducing racial disparities and the misuse of incarceration,” and he vowed that the changes are “just beginning.”

Referencing his plan to bring Middleton on as a special prosecutor, Gascón said he has asked all county law enforcement agencies to turn over lists of the names of officers with a “known history of dishonesty, bias, unreasonable force or any other conduct that may impact their credibility.”