The stepbrother of Tupac Shakur has filed a lawsuit against the man set to go on trial for the rapper’s 1996 killing. The suit is part of an effort to hold the alleged killer and any still unknown perpetrators accountable, Maurice Shakur says.

“Many individuals who were involved have long since passed away, while others have been hard to identify,” the suit states. “Yet, one thing is certain: there remain individuals who were involved in Tupac’s murder who, for 30 years, have not been held accountable for their crimes.”

The wrongful death suit filed by Maurice Shakur against Duane “Keffe D” Davis and dozens of unnamed co-conspirators seeks damages and to reveal “the specific nature and extent of each individual’s involvement – and the identities of additional individuals” who were involved.

Shakur was gunned down just off the Las Vegas strip on 7 September 1996 after attending a Mike Tyson fight at the MGM Grand hotel. He was traveling to an afterparty with a group that included Death Row Records founder Marion “Suge” Knight, when a white Cadillac pulled up next to their BMW at a red light and fired eight shots. Shakur was hit four times and died days later.

The case remained unsolved for decades, despite drawing intense speculation and conspiracy theories. But in 2023, authorities in Nevada announced they had arrested Davis, a former gang leader and one of the last surviving witnesses to the crime. He was indicted for murder for allegedly orchestrating the drive-by shooting.

Davis, who has pleaded not guilty, had described his involvement in the drive-by shooting in a 2019 memoir. Prosecutors allege that he admitted to serving as the “on the ground, on-site commander of the effort to kill Tupac”, after the rapper was involved in a fight with his nephew, Orlando “Baby Lane” Anderson.

Afeni Shakur, the artist’s mother, sued Anderson, who was a longtime suspect in the killing, in 1997. But the case ultimately did not proceed as Anderson was shot and killed in a separate incident in 1998.

The lawsuit filed by Maurice Shakur argues new information, including grand jury testimony and the recent Netflix documentary series on Sean Combs, has “revealed the existence of a broader, more complex conspiracy to murder Tupac”.

Davis’s trial in the criminal case against him is set to begin in August. His attorneys have said Davis made false public statements regarding his presence in the Cadillac involved in the shooting, and that he benefited from claiming to be present.