Lawyers in the District filed a class-action lawsuit Wednesday against the Washington Metropolitan Area Transit Authority on behalf of nine African American men who say the agency’s criminal background screening policy violates their civil rights.

The suit alleges that Metro has an “overly broad, unjustifiably rigid and unduly harsh” employee screening policy that disproportionately bars well-qualified black workers from jobs with the agency. The suit also names contractors Diamond Transportation, Executive Personnel Services and First Transit as co-defendants.

“The policy disqualifies many job applicants and employees based on criminal history that is not related to the job at issue or occurred so long ago — in some cases, 20 or 30 years in the past — that it is irrelevant to any fair determination of employee honesty, reliability or safety,” according to the complaint filed in U.S. District Court.

The lawsuit comes as the District, San Francisco, Montgomery County and about 70 other municipalities have passed “ban the box” legislation, preventing employers from asking about prior convictions on job applications.

The nine plaintiffs say they were fired from jobs or denied employment with Metro after the transit authority conducted a criminal background check. Most of the men have been convicted of nonviolent criminal drug felonies, but some have also been found guilty of assault, robbery or brandishing a firearm, according to the complaint.

There could be 150 or more other plaintiffs, said Matthew Handley, director of litigation for the Washington Lawyers’ Committee for Civil Rights and Urban Affairs, which is representing the men along with the NAACP Legal Defense Fund and Arnold & Porter.

The civil rights concern, Handley said, is most worrisome for applicants who may have been disqualified because of a past nonviolent drug conviction. African Americans account for more than 90 percent of drug convictions in the District, even though usage rates are about the same for blacks and whites, according to a 2013 study by the Washington Lawyers’ Committee.

“We do believe that criminal background information can be a legitimate tool for employers, but it is just that WMATA’s policy is unduly rigid and out of step with other jurisdictions,” Handley said.

The ban-the-box legislation approved by the D.C. Council prevents employers from rejecting potential job applicants based on their criminal background but allows screening after a job interview.

A Metro spokeswoman said the agency does not comment on pending litigation, referring reporters to testimony that General Manager Richard Sarles gave to city officials earlier this year.

The agency changed its policy on background screenings in 2011, trying to eliminate the uncertainty of a “case-by-case” approach while trying to maintain safety for employees and the public, Sarles said. He added that the agency has not fired anyone because of a criminal conviction before Metro employment.

“We believe in, and the policy provides, for second chances,” Sarles told a D.C. Council committee when officials took up the issue in February. “All disqualified candidates are given the opportunity to submit an appeal with supporting documents to Metro for review.”

Plaintiff Erick Little, 47, said the agency rescinded a job offer as a bus driver because he had a 27-year-old felony drug conviction.

“I felt ashamed and heartbroken that WMATA could not see past my 19-year-old self to the man I’ve worked to become today,” said Little, who works as a bus driver in Montgomery County and coaches Little League. “WMATA sent me and many others the message that the first mistake you make is the only thing that matters.”

Get updates on your area delivered via e-mail