Wallace’s murder remains unsolved and there are many theories regarding the identities and motives of the murderers.
In 2002, Randall Sullivan released LAbyrinth, a book compiling information regarding the murders of Wallace and Shakur based on evidence provided by retired LAPD detective, Russell Poole. Sullivan accused Marion “Suge” Knight, co-founder of Death Row Records and an alleged Bloods affiliate, of conspiring with David Mack, an LAPD officer and alleged Death Row security employee, to kill Wallace and make Shakur and his death appear the result of a fictitious bi-coastal rap rivalry. Sullivan believed that one of Mack’s associates, Amir Muhammad (also known as Harry Billups), was the hitman based on evidence provided by an informant, and due to his close resemblance to the facial composite. Filmmaker Nick Broomfield released an investigative documentary, Biggie & Tupac, based mainly on the evidence used in the book.
An article published in Rolling Stone by Sullivan in December 2005 accused the LAPD of not fully investigating links with Death Row Records based on evidence from Poole. Sullivan claimed that Sean Combs “failed to fully cooperate with the investigation” and according to Poole, encouraged Bad Boy staff to do the same. The accuracy of the article was later refuted in a letter by the Assistant Managing Editor of the LA Times accusing Sullivan of using “shoddy tactics”. Sullivan, in response, quoted the lead attorney of the Wallace estate calling the newspaper “a co-conspirator in the cover-up”.
In March 2005, the relatives of Wallace filed a wrongful death claim against the LAPD based on the evidence championed by Russell Poole. They claimed the LAPD had sufficient evidence to arrest the assailant, but failed to use it. David Mack and Amir Muhammad (a.k.a. Harry Billups) were originally named as defendants in the civil suit, but were dropped shortly before the trial began after the LAPD and FBI dismissed them as suspects. In July 2005, the case was declared a mistrial after the judge showed concern that the police were withholding evidence. An attempt to expand the wrongful death lawsuit to include new claims failed in August 2006. The criminal investigation was re-opened in July 2006.
On January 19, 2007, Tyruss Himes (better known as Big Syke), a friend of Shakur who was implicated in the murder by television channel KTTV and XXL magazine in 2005, had a defamation lawsuit regarding the accusations thrown out of court.
On April 16, 2007, relatives of Wallace filed a second wrongful death lawsuit against the city of Los Angeles. The suit also named two LAPD officers in the center of the investigation into the Rampart scandal, Rafael Perez and Nino Durden. According to the claim, Perez, an alleged affiliate of Death Row Records, admitted to LAPD officials that he and Mack (who was not named in the lawsuit) “conspired to murder, and participated in the murder of Christopher Wallace”. The Wallace family said the LAPD “consciously concealed Rafael Perez’s involvement in the murder of … Wallace”. A U.S. district judge dismissed the lawsuit on December 19, 2007. Los Angeles Judge Florence-Marie Cooper reinstated the lawsuit on May 9, 2008. With the agreement of both sides, the lawsuit was dismissed April 5, 2010 without prejudice to refiling.