District attorney to review all prior cases of former Memphis police officers charged in Tyre Nichols' death

The local district attorney's office in Tennessee's Shelby County announced Thursday that it will review all prior cases -- closed and pending -- of the five former Memphis police officers charged in the death of Tyre Nichols.

"This is still an active and ongoing investigation," the Shelby County District Attorney's Office said.

Tadarrius Bean, Demetrius Haley, Emmitt Martin III, Desmond Mills Jr. and Justin Smith were involved in the traffic stop that allegedly led to Nichols' death last month. Nichols was arrested in Memphis on the evening of Jan. 7, after officers attempted to make a traffic stop for reckless driving near the area of Raines Road and Ross Road, according to separate press releases from the Memphis Police Department and the Tennessee Bureau of Investigation. A confrontation unfolded as the officers approached Nichols, who ran away. Another confrontation occurred when the officers pursued Nichols and ultimately apprehended him, police said.

After the incident, Nichols "complained of having a shortness of breath" and was transported by ambulance to Memphis' St. Francis Hospital in critical condition, according to police.

Due to Nichols' condition, the Shelby County District Attorney's Office was contacted and TBI special agents were subsequently requested to conduct a use-of-force investigation, according to the TBI.

Nichols "succumbed to his injuries" on Jan. 10, the TBI said. He was 29.

Local, state and federal authorities continue to investigate the Jan. 7 traffic stop and Nichols' death.

The Memphis Police Department announced on Jan. 21 that it had fired Bean, Haley, Martin, Mills and Smith following its administrative investigation into the incident.

On Jan. 26, all five former officers were arrested and charged with several felonies, including second-degree murder. They were booked into the Shelby County Jail, with bonds set at $350,000 for Martin and Haley and $250,000 for Bean, Mills and Smith, according to a TBI press release. Online jail records show they have since been released after posting bond.

Mills' lawyer, Blake Ballin, and the attorney for Martin, William Massey, told reporters last month that their clients were "devastated" about the charges and will be pleading not guilty. The defense attorneys representing Bean, Haley and Smith have either declined to comment or did not respond to ABC News' previous requests for comment.

Video of the Jan. 7 traffic stop, comprised of footage from the city's surveillance cameras and the former officers' body-worn cameras, was made public on Jan. 27. The graphic video, which shows the officers beating Nichols, has sparked nationwide outrage.

According to a preliminary independent autopsy commissioned by Nichols' family and released by their lawyers, he suffered from "extensive bleeding caused by a severe beating."

Neither the independent autopsy report nor official autopsy report have been publicly released.

Bean, Haley, Martin, Mills and Smith were part of the SCORPION Unit, an acronym for Street Crimes Operation to Restore Peace In Our Neighborhoods launched in 2021 by the Memphis Police Department. The goal of the unit was created to address violent crimes in the city in a 50-person unit that operates seven days a week. According to the Memphis Police Department, the five former officers violated policies for use of force, duty to intervene and duty to render aid. Other officers are under investigation for department violations as well.

According to a Tennessee Peace Officers Standards and Training Commission document obtained by ABC News, Haley took two pictures on his personal cellphone of the "obviously injured" Nichols after he had been handcuffed. He admitted to sharing a photo in a text message with five people -- a civilian employee, two Memphis police officers and a "female acquaintance" -- while an administrative investigation uncovered that a sixth person also received the same photo, according to the document.

The actions violated a Memphis Police Department regulation regarding confidential information, which states that officers cannot share information relating to official police matters "without prior approval or subpoena, except to authorized persons," according to the document, which was part of the process to decertify Bean, Haley, Martin, Mills and Smith.

On Jan. 30, the Memphis Police Department announced that Preston Hemphill, another officer involved in the Jan. 7 traffic stop, and one unidentified officer were relieved of duty amid the ongoing investigation into Nichols' death. The Memphis Fire Department also announced that three of its members who were deployed in an ambulance to the scene that night -- EMTs Robert Long and JaMicheal Sandridge, as well as Lt. Michelle Whitaker -- have been fired for failing to properly assess Nichols as he lay beaten on the ground.

Seven additional Memphis police officers could face discipline in connection with Nichols' death, according to the city's chief legal officer, Jennifer Sink.

ABC News' Kiara Alfonseca, Whitney Lloyd and Armando Tonatiuh Torres-García contributed to this report.