After the beating death of Tyre Nichols by five Memphis police officers in January and other abuses that have come to light, the police department is under mounting pressure to change its culture.
The five former police officers face charges of excessive force, deliberate indifference and witness tampering for the January death of the 29-year-old Nichols.
The Justice Department said its investigation will focus on the Memphis Police Department's use of force, its stops and arrests and whether the department engages in discriminatory policing.
The 29-year-old's official cause of death was ruled a homicide, according to the report released Thursday by the West Tennessee Regional Forensic Center.
The lawsuit compared Nichols' fatal police beating to the 1955 killing of Emmett Till, saying the 29-year-old suffered a beating "endured at hands of a modern-day lynch mob."
Black police chiefs, commissioners, sheriffs and commanders from across the country are set to meet this weekend in Detroit for the annual CEO symposium of the National Organization of Black Law Enforcement Executives.
Decertification hearings for others investigated in his death are pending. Decertification prevents officers from going to work in the same jurisdiction. They can still get police jobs out of state.
Lt. DeWayne Smith served as a supervisor on the now-deactivated SCORPION unit — the specialized police unit responsible for conducting the traffic stop that ultimately lead to Nichols' death.
The 20-some hours of video and audio footage were set to be released Wednesday alongside other documents from the city's investigation into the officers involved in the 29-year-old Black man's death.
They were arraigned on charges of murder, assault and other felonies. Tyre Nichols died three days after officers beat him following a Jan. 7 traffic stop.
Two sheriff's deputies who have been suspended for five days failed to keep their body cameras activated after they went to the location where Nichols had been beaten by Memphis police, officials say.
The Shelby County District Attorney's Office says it will review all "closed and pending" cases of the five former Memphis police officers charged in Nichols' death. Four had prior violations at work.
Preston Hemphill had been suspended as he was investigated for his role in the Jan. 7 arrest of Nichols, who died in a hospital three days later. Five Memphis officers have already been fired.