LAS VEGAS (AP) — An ex-gang leader is seeking to have all the charges against him dismissed in the 1990s killing of rap music icon Tupac Shakur.

Attorney Carl Arnold filed the motion on Monday in the District Court of Nevada to dismiss charges against Duane Davis in the 1996 shooting of Shakur. The motion alleges “egregious” constitutional violations because of a 27-year delay in prosecution. The motion also asserts a lack of corroborating evidence and failure to honor immunity agreements granted to Davis by federal and local authorities.

“The prosecution has failed to justify a decades-long delay that has irreversibly prejudiced my client,” Arnold said in a news release. “Moreover, the failure to honor immunity agreements undermines the criminal justice system’s integrity and seriously questions this prosecution.”

Clark County District Attorney Steve Wolfson didn’t immediately respond to an email seeking comment on the filing. He has said evidence against Davis is strong and it will be up to a jury to decide the credibility of Davis’ accounts of the shooting including those in a 2019 memoir.

Davis is originally from Compton, California. He was arrested in the case in September 2023 near Las Vegas. He has pleaded not guilty to first-degree murder and has sought to be released since shortly after his arrest.

Davis is accused of orchestrating and enabling the shooting that killed Shakur and wounded rap music mogul Marion “Suge” Knight after a brawl at a Las Vegas Strip casino involving Shakur and Davis’ nephew, Orlando “Baby Lane” Anderson.

Authorities have said that the gunfire stemmed from competition between East Coast members of a Bloods gang sect and West Coast groups of a Crips sect, including Davis, for dominance in a genre known at the time as “gangsta rap.”

In interviews and a 2019 tell-all memoir that described his life as a leader of a Crips gang sect in Compton, Davis said he obtained a .40-caliber handgun and handed it to Anderson in the back seat of a car from which he and authorities say shots were fired at Shakur and Knight in another car at an intersection near the Las Vegas Strip. Davis didn’t identify Anderson as the shooter.

Shakur died a week later in a nearby hospital. He was 25. Knight survived and is serving a 28-year prison sentence in connection with the killing of a Compton man in 2015.

Anderson denied involvement in Shakur’s death and died in 1998 at age 23 in a shooting in Compton. The other two men in the car are also dead.

A Las Vegas police detective testified to a grand jury that police do not have the gun that was used to shoot at Shakur and Knight, nor did they find the vehicle from which shots were fired.