More than two months after deputies were sentenced for torturing two Black men in central Mississippi, federal prosecutors have widened their investigation and may sue the Rankin County sheriff’s department for civil rights violations, a serious escalation that could lead to federal monitoring.

Todd Gee, the U.S. attorney for the Southern District of Mississippi, talked about the possibility at a meeting last month, where he urged local residents who attended to come forward if they had experienced violence or discrimination at the hands of deputies.

More than 50 people, including defense attorneys and civil rights advocates, packed into a library outside Jackson, Miss. Some shared stories of being harassed or falsely accused of crimes by deputies, according to several people who attended the meeting, which was closed to the press.

“Information from people like you can make a difference,” Mr. Gee told the crowd, according to video of the meeting obtained by reporters.

He explained that if deputies’ misconduct had been going on for years it could be evidence of a pattern of civil rights violations that could lead to a case against the department.

Rather than focusing on individual acts of misconduct, “pattern or practice” investigations determine whether civil rights violations have become part of an agency’s overall culture. Prosecutors can sue a department and seek a consent decree, a legally binding agreement that would force the department to implement reforms.