Legendary rapper Tupac Shakur knew his assassin, according to a new documentary.
Shakur was shot to death on Sept. 7, 1996, while driving through Las Vegas, recalls the Daily Mail.
Various people have been implicated in the shooting over the years, most prominently Biggie Smalls, aka the Notorious BIG.
His murder has remained unsolved because of police inaction, according the Sept. 21 episode of "Snapped: Notorious," reports TMZ.
The allegations are made by Shakur's friends, family and music business colleagues in the two-hour documentary, which examines the night of Shakur's death.
Among the interviewees are those who were the last to see him alive, including close friends and rappers Danny Boy and Yo-Yo, DJ Mister Cee, Shakur's first manager, Leila Steinberg, music journalist Toure and others.
The documentary alleges that the slain rapper nodded "yes" when asked if he knew who shot him.
Smalls, a former friend of Shakur, has long been suspected due to the pair's high-profile feud.
In 1995, Shakur was shot while being robbed, and he accused Smalls of being complicit in the crime.
The animosity intensified when Shakur signed to Suge Knight's Death Row records, a competitor of Biggie's label, Bad Boy records.
In addition, only months before his death, Shakur released the track "Hit 'Em Up," in which rapped about having sex with Small's then-estranged wife.
Smalls, who was himself murdered during a drive-by shooting the following year, denied any involvement in the shooting.
Another possible suspect was Orlando Anderson, a member of the Southside Crips gang, as reported in 2002 by the Los Angeles Times, notes the Daily Mail.
Shakur, Knight and several of their entourage allegedly beat up Anderson the same day as the shooting. However, Las Vegas police discounted the beating from their investigation, and did not pursue claims by one of Shakur's friends that he had witnessed the shooting.
Anderson, who denied the allegations, was killed in a gang shooting in 1998.
Although the documentary places much of the blame on the police for Shakur's murder being unsolved, it also notes that the rapper himself was not exactly helpful. When the cop who found him after the shooting asked who his killer was, Tupac reportedly replied, "F**k you."
But the general consensus among those interviewed is that the police know who the killer is, and are covering it up. As Shakur's occasional collaborator, EDI Mean, summed it up: "I'm absolutely positive they know what happened. This is America. We found Bin Laden."