Despite its high profile, the murder of Tupac Shakur remains a case shrouded in mystery. This September will mark 18 years since the Las Vegas shooting that led to the rap star's death, and still no one has been arrested for the murder. Theories abound, but just as many questions remain.

One new tidbit has come to light after all of these years, though. Chris Carroll, a now-retired officer in the Las Vegas Police Department, says 'Pac's last words were truly memorable: "F--k you."

This comes according to Carroll, who was on patrol on a bike the night of the shooting -- which occurred following a Mike Tyson fight at the MGM Grand -- and who was the first officer to arrive at the scene. Carroll spoke with Vegas Seven about that night, and recalled opening the 25-year-old's bullet-ridden passenger side door, simply to have him fall into his arms, bloody and nearly lifeless:

So I’m looking at Tupac, and he’s trying to yell back at Suge, and I’m asking him, ‘Who shot you? What happened? Who did it?’ And he was just kind of ignoring me. He was making eye contact with me here and there, but he’s trying to yell at Suge. And I kept asking over and over, ‘Who did this? Who shot you?’ And he basically kept ignoring me. And then I saw in his face, in his movements, all of a sudden in the snap of a finger, he changed. And he went from struggling to speak, being noncooperative, to an ‘I’m at peace’ type of thing. Just like that.

He went from fighting to ‘I can’t do it.’ And when he made that transition, he looked at me, and he’s looking right in my eyes. And that’s when I looked at him and said one more time, ‘Who shot you?’

He looked at me and he took a breath to get the words out, and he opened his mouth, and I thought I was actually going to get some cooperation. And then the words came out: ‘F--k you.’

After that, he started gurgling and slipping out of consciousness. At that point, an ambulance showed up, and he went into unconsciousness.

Carroll also opens up with his reflections on and memories about what went down. He had never spoken publicly on the events of that evening before.

For those hoping the information Carroll offers could help solve the murder -- not so fast. "Now it’s been almost 18 years," he said. "There’s clearly never going to be a court case on this."