The conviction of Duane “Keffe D” Davis in Las Vegas has brought an end to one of the world’s most famous unsolved murder cases.

He was found guilty of the murder of rapper Tupac Shakur, who died when the black BMW he was travelling in was sprayed with bullets in a drive-by shooting in 1996.

“This is huge. It was a tough case. It’s a cold case,” former prosecutor Neama Rahmani told the BBC. “We’re talking about the greatest rapper of all time, an icon, and not a single arrest or prosecution for 30 years.”

The conviction gives closure to Shakur’s family, and has prompted questions from observers as to what it could mean for an almost identical case – the unsolved murder of Notorious B.I.G. or Biggie Smalls, also known by his legal name of Christopher Wallace.

Wallace, a New Yorker, was once one of Shakur’s friends, but the two became rivals and embodied the East Coast-West Coast feud that dominated 1990s hip-hop. Wallace was killed in Los Angeles a few months after Shakur and in similar circumstances – a drive-by shooting. No one has ever been charged.

“Tupac’s murder and Biggie’s murder are two of the great cultural touchstones of our lives,” said Justin Tinsley, a journalist for ESPN’s Andscape and the author of “It Was All a Dream: Biggie and the World That Made Him.”

“Those two men, they were so unique, talented, and impactful, separately,” Tinsley told the BBC. “But it’s impossible to tell each of their stories without telling the other’s.”

“When you talk about these cases, they’re always going to be connected because there are so many mutual figures involved with them, and ancillary figures,” he said.

Theorists have long believed the two murders were linked. Wallace’s name came up during Duane Davis’ trial. He and Davis were at the same party the night Wallace was killed, and police interviewed Davis about it.

The investigator who conducted that interview even testified at the Tupac murder trial.

The breakthrough in finally solving the Shakur case largely came down to one thing: Davis’ own words.

Through documentaries with the media, his own memoir, podcasts and even a secret police interview, he acknowledged his role in Shakur’s death.

Davis said he tossed a firearm in the backseat and his nephew, Orlando Anderson, used the gun to fatally shoot Shakur as they pulled up alongside his vehicle in Las Vegas on 7 September, 1996.

Anderson was shot dead in 1998, having denied killing Shakur.

During the trial, there were no eye-witnesses to place Davis as being in the car, no murder weapon presented, no video or photo evidence. His defence team went as far as to argue there wasn’t even proof that he was in Las Vegas that night.

Rahmani said it was a difficult case to prosecute. He noted the rumours and speculation surrounding Davis were nothing new and had been around for decades – but the decision to charge him and go to trial was an “uphill climb” – a gutsy move – for prosecutors.

“Look, when you’re a prosecutor, you’re expected to win every time. They made a difficult decision to charge a case that a lot of people thought might be a loser,” he explained. “And they got justice, where other people didn’t even bother trying.”

Davis’ attorney Michael Sanft asked the jury to consider “what facts do you have?” He urged the panel, before they decided their guilty verdict, to discredit his client as a liar who told tales to sell books and make money.

“There’s no proof,” he argued to the jury.

The moment the guilty verdict was read in court, there was an outpouring of emotion among Shakur’s family. Some cried and wiped tears with tissues. Others hugged and held hands. A family member embraced one of the prosecutors in the case.

At a press conference on Tuesday, Clark County District Attorney Steve Wolfson thanked the judge, prosecutors and Shakur’s family members, who he said were very relieved and “finally have justice.”

“Their loved one was murdered,” he said. “They waited 30 years for a trial. It’s very understandable that they were relieved.”

Trial lawyer attorney Shaun Kent said the case really evolved with each interview and moment that Davis decided to talk about the case.

“There are no other witnesses, besides him,” Kent told the BBC before the trial, noting that the “strongest witness against him, is him”.

Rahmani believed Davis likely would have never faced charges if he had stayed silent.

“He really couldn’t stop himself,” Rahmani added. “Even when he was arrested and in custody, he was giving interviews.”

Much of the Shakur trial forced the jury to place themselves back in the 1990s, at a time of intense gang violence that had infiltrated roots into hip-hop music and rivalries between East-Coast and West-Coast rappers.

It was a time of deep-rooted mistrust in policing and a street code that forbade reporting to authorities.

Even Shakur, after being hit multiple times in the drive-by shooting that would later kill him, refused to talk to authorities. “We’ll take care of it,” he said in an ambulance as an officer tried to question him.

The silence was echoed months later in the shooting death of Biggie Smalls.

Biggie, one of the biggest East Coast rappers, was leaving an after-party in Los Angeles for the Soul Train Music Awards, when a black Chevrolet pulled up to his vehicle at a red light and opened fire on 9 March, 1997. It was almost exactly six months after the shooting that killed Shakur, one of the biggest West Coast rappers.

Both were Grammy-nominated artists at the top of their genre, making millions and receiving constant radio play. Their feud spilled over into their lyrics, and also led to threats and physical violence.

Violence erupted on the streets of Los Angeles following both shootings, as street gangs sought to hold one another accountable for the rappers’ deaths.

For years, neither murder led to arrests or convictions, just rumours and conspiracies.

“People will search for closure in any way they can get it,” Tinsley said. “People are trying to make sense of it for 30 years.”

Like Shakur’s death, countless theories and names have surrounded the death of Biggie in Los Angeles, but the Los Angeles Police Department (LAPD) have not made any arrests.

“It’s really a stain on the LAPD. The fact that this could happen and not a single arrest was made and no one was prosecuted,” Rahmani said, noting Biggie’s killing happened on a public street in the middle of the second most populous US city.

“Prosecutors don’t like to lose,” Rahmani explained. “But, maybe this [Tupac’s conviction] will embolden folks in Los Angeles to maybe take another look at it, a cold case that’s coming up on 30 years.”

Asked about the cases and whether the Tupac murder conviction could revive Biggie’s death, the LAPD told the BBC that it was aware of the conviction and the investigation into Biggie’s case remained active.

“The murder of Christopher Wallace remains an open, unsolved case within LAPD’s Robbery-Homicide Division,” Lt Elpidio Orozco said, urging anyone with any tips to call authorities.

Though Wallace’s case has gone cold, the public’s interest has not.

“They’ve been gone longer than they’ve been alive,” Tinsley said, “But the enduring mythology around these guys and their deaths will always be a topic of conversation.”

Kayla Epstein contributed to this report.

Get all the latest trial updates on the BBC Sounds ‘Fame Under Fire: The Tupac Murder Trial‘ podcast available wherever you get your BBC podcasts.