The prosecutor in Shelby County, Tenn., dropped more than 30 cases connected to the five former Memphis police officers who were charged with second-degree murder in the death of Tyre Nichols, CNN reports.

District Attorney Steve Mulroy’s office reviewed approximately 100 cases involving the terminated officers. In addition to the dismissals, he decided to reduce charges in about a dozen of the cases

“As in any such case, the primary consideration is concern about the credibility as witnesses of discharged officers,” the DA’s office said.

The case dismissals come more than six months after Memphis officers were seen on video brutally beating Nichols, a 29-year-old unarmed Black motorist, in January. Nichols died three days later from his injuries.

The Memphis Police Department fired seven officers in connection with the incident. Five of them, all African American, were charged with second-degree murder and other offenses.

The five officers charged in Nichols’ death were members of the police department’s SCORPION unit. It was a special street crimes unit launched in 2021 to combat surging homicide rates. The department disbanded the unit following nationwide outrage over Nichols’ death. Members of the unit were often accused of using heavy-handed policing tactics targeting Black people.

In July, the U.S. Justice Department launched a pattern or practice investigation of Memphis and the Memphis Police Department to determine whether the police systemically uses excessive force and discriminates against Black residents.