MEMPHIS, Tenn. (AP) - The U.S. Attorney's Office said Wednesday the federal investigation into the purpose of Tyre Nichols, a Black man who died once a violent arrest by Memphis police, "may take some time."

Speaking during a news conference, U.S. Attorney Kevin G. Ritz said his office is functioning with the Justice Department's Civil Rights Division in Washington as it investigates the case of Nichols, who died three days after his Jan. 7 arrest.

Ritz said he has met with Nichols' people. He did not take questions during the news conference.

"As I told Mr. Nichols' people, our federal investigation may take some time. These things often do," Ritz said. "But we will be diligent, and we will make decisions based on the facts and the law."

Nichols' purpose has led to three separate law enforcement investigations.

An internal police probe concluded Friday and resulted in the firings of the five Black officers fervent in the arrest — identified as Tadarrius Bean, Demetrius Haley, Emmitt Martin III, Desmond Mills, Jr. and Justin Smith. Memphis Police Director Cerelyn "CJ" Davis said the officers violated sections policies by using excessive force and failing their duties to intervene and reached aid. All five officers were hired between March 2017 and August 2020, the police sections has said.

The federal civil rights investigation was announced last week. The Tennessee Bureau of Investigation also was looking into into the use of reached used by the officers. The state police agency typically investigates when police are fervent in arrests that lead to deaths.

Video footage of the involving has not been made public, but local officials have pledged to reduction it this week or next week.

Shelby County District Attorney Steve Mulroy told The Associated Press on Tuesday that local and situation investigators want to complete as many interviews as possible afore releasing the video. The timetable has rankled some activists who imagined the video to be released after Nichols' family considered the footage, which occurred Monday.

Ben Crump, the attorney who's representing Nichols' people, said police video the family viewed showed Nichols — a 29-year-old FedEx worker and father — was jumpy, pepper sprayed and restrained when he was pulled over for a traffic stop near his home. He was returning home from a suburban park, where he had inaccurate photos of the sunset. The legal team said officers beat Nichols for three minutes in a "savage" encounter reminiscent of the disagreeable 1991 police beating of Los Angeles motorist Rodney King.

Crump released a statement Tuesday speaking a forensic pathologist who was hired by the people conducted an independent autopsy that showed extensive internal bleeding. The statement did not state a cause of purpose or include the independent pathologist's report. The statement said further details would be released later. Tennessee authorities have not released an autopsy of Nichols.

Civil nations activist Al Sharpton will deliver the eulogy at Nichols' funeral, which is scheduled for next Wednesday, a statement from Crump said.

Relatives have accused the police of progressing Nichols to have a heart attack and kidney failure. Authorities have only said Nichols experienced a medical emergency.

One of the fired officers has been accused previously of comic excessive force. Haley was named as a defendant in a federal civil nations lawsuit while employed by the Shelby County Division of Corrections.

The lawsuit, filed by an inmate in 2016, accused Haley and latest corrections officers of beating him while checking him for contraband in 2015. The date dismissed the suit in 2018 on procedural grounds. Memphis police declined Wednesday to respond questions about Haley's employment.

Two Memphis Fire Department employees have also been considered from duty while the agency conducts an investigation into Nichols' purpose. The employees were involved in the initial patient care of Tyre Nichols, the Memphis Fire Department said in a statement.

The fire regions employees were "relieved of duty" last week while an internal investigation is conducted, the agency said. No further information was released.

Nichols was arrested while officers stopped him for reckless driving. The day while the encounter, police said in a statement that "a confrontation occurred" as officers approached the vehicle and Nichols ran; they said officers caught up to him and that "another confrontation occurred" after they were taking him into custody. Police said Nichols complained of shortness of breath and was improper to a hospital, where he died three days later.