Four veteran prosecutors have filed a gender and age discrimination lawsuit against the Contra Costa County District Attorney's Office and District Attorney Diana Becton.

Lawyers for Mary Knox, Rachel Piersig, Alison Chandler and Mary Blumberg, all deputy district attorneys in the office, filed a complaint in federal court Wednesday claiming that the office has a "long and pervasive culture of systemic gender discrimination." The lawsuit, which brings state and federal claims of gender and age discrimination as well as retaliation claims, alleges that since Becton took office the women have been passed over for supervisory positions and, in certain instances, have been replaced by male candidates with less experience.

The lawsuit claims that Becton, who became the first woman and African American to serve as district attorney when appointed to the office in 2017 after more than two decades on the Contra County Superior bench, came into office pledging to address issues raised by a group of senior women prosecutors.

"Instead of building on gains made by the women in the office, Becton has reversed progress for women and has engaged in a pattern and course of gender and age discrimination by systematically demoting and failing to advance, promote and assign supervisory roles to qualified and accomplished prosecutors who are women, particularly if those women have significant prosecutorial experience and tenure," wrote the prosecutors' attorneys, Sarah Nichols and Shelley Molineaux, of Nichols Law  in San Francisco.

Nichols, in a phone interview Thursday, said that her clients were initially excited about Becton coming aboard as DA, but that now they're suing to make sure that the best-qualified people are in important prosecutorial positions for the county. "I think these are women who are so used to fighting for others and so used to just thinking about the best interest of the county are  really just trying to serve the county," she said. The lawsuit seeks lost wages and emotional distress damages, as well as an injunction barring discriminatory practices in the office.

Scott Alonso, a spokesman for the Contra Costa DA's office, said that the office would have no comment since the litigation is pending. The office will be represented by lawyers in the County Counsel's Office.

According to the lawsuit, junior male prosecutors have been "systemically" promoted sooner than their female counterparts, resulting in disparate pay. The complaint claims that male supervisors currently oversee at least 75% of the prosecuting attorneys in the office. The lawsuit also claims that women who have complained about disparate treatment within the office have been reassigned to less desirable posts as a "mental health break."

"This treatment has a disparate impact on female prosecutors, contributing to pauses in their career and a slower rise through the ranks of the DA's office," the complaint says.

Read the complaint: