MEMPHIS, Tenn. (AP) — A judge on Thursday pushed back for four months the federal court trial of four former Memphis police officers charged with civil rights violations in the beating death of Tyre Nichols.

During a hearing, U.S. District Judge Mark Norris changed the trial date in the highly publicized police beating and death from May 6 to Sept. 9.

Norris made the change after defense lawyers asked for more time to effectively prepare their case, a process they say includes review of 800 gigabytes of video, documents and other evidence given to them by federal prosecutors.

Stephen Ross Johnson, the lawyer for former officer Emmitt Martin, told Norris that the officers’ rights to a speedy trial were subservient to their right to a fair trial.

“This case has a number of moving parts,” Johnson said. “We just need additional time.”

Police video showed officers yanked Nichols out of his car during a traffic stop on Jan. 7, 2023, after he was pulled over for alleged reckless driving. Nichols was pepper-sprayed and hit with a stun gun, but he managed to get away and run toward his house nearby. Officers caught up with Nichols and punched him, kicked him and hit him with a police baton, video showed.

Nichols died three days later at a hospital. An autopsy report showed Nichols died from blows to the head, and that the manner of death was homicide.

Memphis’ police chief has said that the department couldn’t substantiate any reason for the stop.

Along with Martin, Tadarrius Bean, Demetrius Haley, Desmond Mills Jr. and Justin Smith were fired after Nichols’ death. The five were indicted in September on federal charges that they deprived Nichols of his rights through excessive force and failure to intervene, and obstructed justice through witness tampering. They also have been charged in state court with second-degree murder.

Mills pleaded guilty to federal charges in November. Mills also intends to plead guilty in state court and could testify against his four ex-colleagues, who have pleaded not guilty.

Nichols was Black. The five officers also are Black.

Defense attorneys for the four officers have filed several pre-trial motions, including efforts to have charges dropped, exclude expert witnesses and change the May 6 trial location.

Norris ruled last week against Haley’s motion to exclude expert testimony at the federal trial. Lawyer Michael Stengel argued that prosecutors missed a deadline to say they were seeking expert testimony. The motion said prosecutors told Stengel that “the United States does not at this time intend to introduce any expert testimony,” but they would advise him should that change.

Stengel asked Norris to bar prosecutors from using experts to discuss Nichols’ cause of death, toxicology and DNA test results, whether the officers used unreasonable force, and whether any “alleged force” used against Nichols resulted in his injury or death.

Norris denied the motion after prosecutors disclosed a list of potential expert witnesses, including Memphis Police Department trainers prepared to testify that the officers used force inconsistent with their training and failed to prevent their colleagues from hurting him.

Stengel countered on Wednesday with a motion to exclude expert opinion on use-of-force issues.

Meanwhile, defense lawyers have asked the judge to drop three charges, which include using excessive force, failing to render aid through “deliberate indifference,” witness tampering and obstruction of justice.

Norris was also considering motions to move the trial out of Memphis or bring in an outside jury because of intense media coverage and the public release of video of the beating. Martin’s motion said the trial atmosphere has been “utterly corrupted by press coverage.”

The criminal case is separate from the U.S. Department of Justice’s “patterns and practices” investigation into how Memphis officers use force and conduct arrests, and whether the department in the majority-Black city engages in racially discriminatory policing.