(NewsNation) — Duane “Keefe D” Davis, the man now charged with murder in the death of Tupac Shakur, admitted in a 2019 memoir and in media interviews that he was in the car from which gunfire erupted during the drive-by in Las Vegas that killed Shakur 27 years ago.

Greg Kading, a retired Los Angeles police detective who spent years investigating the killing, believes Davis has “talked himself straight into prison.”

“The strength of this prosecution lies solely on the confession that Keefe D has made since 2009,” Kading said Friday on “Banfield.”

Davis has long been known to investigators as one of four suspects identified early in the investigation into the 1996 killing. Davis isn’t the accused gunman but was described as the group’s ringleader by authorities Friday at a news conference and in court. In Nevada, a suspect can be charged with a crime, including murder, if they help someone commit the crime.

“Duane Davis was the shot-caller for this group of individuals that committed this crime,” said police homicide Lt. Jason Johansson, “and he orchestrated the plan that was carried out.”

Davis himself has admitted in interviews and in his memoir, “Compton Street Legend,” that he provided the gun used in the drive-by shooting.

Police believe the shooting was in retaliation for a brawl earlier in the night between Shakur and Davis’ nephew, Orlando “Baby Lane” Anderson. Davis has said Anderson was in the back seat of the car from which the gunfire erupted, but Anderson denied any involvement. He died two years later.

Driving Shakur’s car was Death Row Records founder Marion “Suge” Knight, who is currently in prison on an unrelated manslaughter charge.

Kading doubts Knight would help with the prosecution of Davis.

“He’s always known,” who was inside the car that night, Kading said. “He looked directly at Keefe D. They locked eyes. … He’s never done anything to try to solve (the killing), so I don’t think we can expect him to now.”

Davis is the last surviving suspect in the shooting. Along with Anderson, Terrence Brown and Deandre Smith later died.

“Keefe D is the last man standing,” Kading said. Shakur’s mother “Afeni has always known that Orlando Anderson was responsible for her son’s murder, but now we are getting all of the conspirators, and Keefe D is going to have to face the consequences of his own involvement.”

Davis denied an interview request Friday from jail, and court records don’t list an attorney who can comment on his behalf.

The Associated Press contributed to this report.