When Sacramento joined the ranks of cities suing Wells Fargo & Co. over allegations of discriminatory mortgage lending practices, it turned last month to a lawyer at a small firm in San Francisco who has become a familiar foe for the bank.

Yosef Peretz, of Peretz & Associates, first sued Wells Fargo in 2010 in the U.S. District Court for the Northern District of California, where he represented a fired employee who accused the bank of opening accounts without customers' permission—the same conduct that would arise six years later in the bank's $185 million settlement with federal regulators and the Los Angeles City Attorney's Office.

In the years since, Peretz has been hired by Miami Gardens, Florida, and Oakland to participate in the lawsuits those cities brought against Wells Fargo, accused of saddling minority borrowers with loans that were costlier than those offered to similarly situated white borrowers.

“I have a lot of experience with Wells Fargo. It helps,” Peretz said in an interview this week.

Yosef Peretz.

Peretz wouldn't comment about his arrangement with Sacramento on its suit, filed on Feb. 23 in the U.S. District Court for the Eastern District of California.

A Wells Fargo spokesman said the cities' lawsuits are based on a “concept being marketed by the same group of plaintiffs' attorneys at no cost to the cities.” Los Angeles brought a similar mortgage discrimination case in 2013, which a federal judge dismissed in 2015—a decision that was later upheld by the U.S. Court of Appeals for the Ninth Circuit.

“The cities' accusations against Wells Fargo do not reflect how we operate in the communities we serve, and we will vigorously defend our long-standing record of fair and responsible lending,” Wells Fargo said in a statement. “We deeply value our community relationships, and are working diligently and consistently with customers, credit counselors, nonprofit organizations and government agencies to expand homeownership opportunities and revitalize distressed neighborhoods.”

Companies routinely complain about partnerships cities and states form with plaintiffs lawyers for investigations and litigation. The chief argument from industry is that state and local governments should be barred from outsourcing public investigations.

On Monday, the U.S. Supreme Court declined to take up Endo Pharmaceuticals Inc.'s challenge to the contract New Hampshire signed with Cohen Milstein Sellers & Toll for an opioid investigation. Endo's lawyers at Arnold & Porter urged the court to “change the face of modern enforcement proceedings by taking profit motive out of the process.” The contract has since been transferred to Motley Rice.

Cohen Milstein is working with Peretz in a suit the city of Oakland filed against Wells Fargo in 2015. Additionally, lawyers from the Center for Constitutional Litigation and Torrance-based Trial & Appellate Resources are involved in the Oakland case, and in the Sacramento case. Matthew Ruyak, an assistant city attorney for Sacramento, was on the city's complaint.

Philadelphia, which sued Wells Fargo last May, hired several plaintiffs firms—including Lieff Cabraser Heimann & Bernstein; Berger & Montague; and Schonbrun Seplow Harris & Hoffman.

For the Philadelphia case, Wells Fargo hired a defense team headlined by Hogan Lovells partner Neal Katyal, who has spearheaded the legal challenges to the Trump administration's travel ban. Also on the defense team are lawyers from Duane Morris and K&L Gates.

Last month, U.S. District Judge Anita B. Brody of the Eastern District of Pennsylvania denied Wells Fargo's motion to dismiss the lawsuit.

Wells Fargo has yet to reveal its defense lawyers in the Sacramento case. The bank has hired Munger, Tolles & Olson and Proskauer Rose to defend it against Oakland in the U.S. District Court for the Northern District of California.

Peretz's client engagements against Wells Fargo are not limited to federal trial courts.

Recently, Peretz represented a former Wells Fargo branch manager who claimed she was fired for blowing the whistle on colleagues who had been opening unauthorized accounts. After the U.S. Department of Labor ordered Wells Fargo to reinstate his client, Claudia Ponce de Leon, and pay her $577,500 in back wages, damages and legal fees, Peretz negotiated a confidential settlement with the bank.

Whether over discriminatory mortgage lending or retaliation against whistleblowers, Peretz said, his cases against Wells Fargo involve “the same types of issues: workers on the branch side, whether those are bankers or mortgage officers, were incentivized to act unlawfully because they wanted to earn commissions.”

Peretz said public-private litigation relationships are “becoming more and more customary when it comes to claims that require a speciality that the counties or the cities don't have, necessarily. It seems like it's kind of a growing area.”