The family of Tyre Nichols, the man who died three days after Memphis police officers beat him following a Jan. 7 traffic stop, has filed a $550-million lawsuit naming the City of Memphis, Police Chief Cerelyn Davis, the five officers involved, two additional officers, and three fire department employees.

The suit, filed Wednesday morning in the U.S. District Court for the Western District of Tennessee, alleges negligence by the city in hiring Davis, along with asserting Davis' culpability in lax hiring processes, and the development of the SCORPION Unit's "oppression style of policing" and poor training, reports the Commercial Appeal.

The lawsuit claims the City of Memphis should have been aware of Davis’ ties to the Atlanta Police Department’s RED DOG Unit stating, “Much like the RED DOG Unit, SCORPION Unit officers were encouraged by the chief of police and supervisors to engage in searches and seizures when there was no basis to do so in violation of the Fourth Amendment.”

Former Memphis police officers Tadarrius Bean, Demetrius Haley, Justin Smith, Emmitt Martin III and Desmond Mills, Jr. have all been charged with one count of second-degree murder, aggravated assault-acting in concert, two counts of aggravated kidnapping, two counts of official misconduct, and one count of official oppression, court records show.

The five officers had been fired by Davis, who said they were directly responsible for “physical abuse of Mr. Nichols.”