(CNN) A Mississippi prosecutor excluded many black jurors from trials for more than 25 years, a lawsuit alleges.
Since District Attorney Doug Evans took office in 1992, "he and his assistants have employed a policy, custom, or use of discriminatorily striking black jurors with peremptory challenges," according to the class action suit brought forth by four black residents and the NAACP Legal Defense and Educational Fund, Inc. (LDF) and the MacArthur Justice Center, representing Attala County's NAACP branch.
The plaintiffs are asking for a judge to order Evans to stop using challenges as a way to remove black jurors. Peremptory challenges allow lawyers to strike a prospective juror without giving a specific reason.
Black jurors were 4.4 times more likely to be struck down than white jurors, the lawsuit claims. And in cases where the defendant was black, the suit says, Evans' strike rate against black jurors was "even more pronounced."
Earlier this year, the Supreme Court ruled that a black death row inmate in Mississippi should get a new trial after Evans engaged in unconstitutional racial discrimination when turning away black jurors from the panels.
The inmate, Curtis Flowers, was tried five times for the 1996 murder of four people inside a furniture store. A conviction stuck after his sixth trial in 2010 and he was sentenced to death.
"The State's relentless, determined effort to rid the jury of black individuals strongly suggests that the state wanted to try Flowers before a jury with as few black jurors as possible, and ideally before an all-white jury," Justice Brett Kavanaugh wrote in the June decision.
One of the black residents suing Evans was in the jury pool for Flowers' third trial, the lawsuit says. She was one of 15 black jurors who were dismissed.
Without the court's intervention, the lawsuit claims, Evans will ignore the Supreme Court ruling and continue discriminatory practices "not just in Curtis Flowers' case, but in every case in the Fifth Circuit Court District in which Black citizens appear for jury service."
CNN has reached out to Evans for comment but has not yet gotten a response.
"It is hard to find a more egregious pattern of a prosecutor's office treating Black jurors like second-class citizens and rigging the jury system," Chris Kemmitt, senior counsel at LDF, said in a statement.
Jury duty and voting are the most "substantial" opportunities residents have to participate in the democratic process, the suit says.
The prosecutor's practices strike "at the heart of the constitutional guarantee that all citizens may participate in self-government regardless of race," it says.
But even before he was elected into his position, the lawsuit alleges Evans made two stops during his 1991 campaign that "foreshadowed hostility towards African Americans."
The first one was at a Council of Conservative Citizens meeting, the lawsuit says.
The Southern Poverty Law Center calls the Council of Conservative Citizens a "crudely white supremacist group," and the group's statement of principles on its website outlines an opposition to "all efforts to mix the races of mankind" and argues the United States' population "should remain European in their composition and character." The Anti-Defamation League says the organization came from the "anti-integrationist White Citizens Councils" of the 1950s and '60s.
Evans also showed up to the Black Hawk Political Rally, the suit says, which was sponsored by the Council of Conservative Citizens.
The rally was a "fundraiser to help pay for white children in Carroll County to attend a private all-white school and evade a federal desegregation order," the suit claims.
Since winning that election, Evans' office has prosecuted more than 400 criminal trials, the suit says.
In 225 of them, the lawsuit says, 29% of jurors struck were white, and 71% were black.
"The statistical disparity in the cases from 1992 through 2017 is inexplicable on non-racial grounds," the suit says. "Absent intervention from this court, Evans will continue to pursue the same discriminatory policy, custom, or usage."
Correction: This story has been updated to accurately reflect the strike rate of black jurors by the Mississippi prosecutor cited in the lawsuit.