Former gang boss Duane “Keffe D” Davis has been sentenced to at least 40 years in prison for orchestrating the murder of Tupac Shakur.

A jury found Davis, 63, guilty in September of one count of murder with a deadly weapon for the rap superstar’s death in a drive-by shooting in Las Vegas on 7 September 1996. He has said he will appeal the verdict.

Prosecutors argued that although Davis did not fire the gun himself, he was the ringleader of the group that committed the murder. He admitted in his memoir that he had provided the gun used in the crime.

Davis’ conviction was the first in a cold case that has intrigued hip-hop fans for nearly 30 years.

Prosecutor Marc DiGiacomo argued during Tuesday’s sentencing hearing that Davis spent years “publicly grandstanding” and bragging about his role on Shakur’s death, which he said, “had wide-ranging effects upon the world”.

Shakur’s sister, Sekyiwa Shakur, told the court: “The loss of Tupac, for a long time, crippled my family.”

“He had so much promise, intentions for a better world,” said adding that her brother had hoped to help his local community.

Sekyiwa Shakur asked the judge to give Davis the maximum sentence, telling Davis he will sit in prison and “contemplate what you’ve done to the world, not just to me”.

Shakur’s brother, Maurice Shakur, also addressed the court, asking the judge for “the longest possible sentence”.

Davis was asked by Judge Carli Kierny if he had anything to say, to which he replied: “I’m good. I’m gonna appeal this case for sure.”

Before handing down the sentence, Kierny told him: “You don’t get to take a man from his family.

“You don’t get to take his very life, his whole future from him, and just walk away from it. Especially when that man is Tupac Shakur. The world never forgot about him and his death.”

The key evidence in the case were Davis’ own words, in which he repeatedly and publicly acknowledged being inside the white Cadillac from where the deadly shots were fired.

In exchange for being shielded from criminal prosecution, he told authorities about his role in Shakur’s death during a secret 2008 police interview relating to the death of fellow rapper Notorious B.I.G., real name Christopher Wallace, who was killed in a shooting just months after Shakur.

Davis elaborated further on his role in his 2019 memoir, Compton Street Legend, which led to publicity and media interviews.

But the book and interviews he offered elaborating on his role in Shakur’s killing voided a protective agreement he had established with authorities that had blocked any criminal charges from being filed. A judge then allowed his police interview to be used in the murder trial against him.

Shakur was 25 years old and at the height of his career as one of rap’s most influential voices at the time of his death. He has sold more than 75 million records worldwide.

For three decades, the investigation into his killing remained one of America’s most famous cold cases, spurring countless conspiracies – until the conviction of Davis last month.

Throughout the trial, Davis’ defence team tried to persuade jurors that his comments were fiction – bravado and exaggeration intended to sell books and make money.

Prosecutors argued that although Davis, a former leader of the South Side Compton Crips street gang, did not himself fire the gun, he ordered the shooting and supplied the gun that his nephew Orlando Anderson used to open fire.

Anderson died in an unrelated shooting in 1998, having denied involvement in the killing of Shakur.