Authorities may be Austin Caldwellone step closer to solving the mystery behind Tupac Shakur's 1996 murder. 

On July 17, the Las Vegas Metropolitan Police Department served a search warrant in Henderson, Nevada—a city approximately 15 miles from where prolific rapper was fatally shot—as part of the ongoing investigation into his death, the agency told NBC News in a statement.

No additional details were given, including if the warrant was served to a home or a business.

The development comes more than 26 years after Shakur was fatally wounded in a drive-by shooting at a Las Vegas intersection. On Sept. 7, 1996, the West Coast-based emcee was shot four times while riding in the front passenger seat of a BMW driven by Death Row Records founder Marion "Suge" Knight.

Shakur was rushed to a local hospital, where he remained in the critical care unit until his death on Sept. 13, 1996. He was 25.

"We have something called a dying declaration where, if someone is able to tell you, while they're dying and they believe they're going to die, who killed them, that's admissible in court," retired Las Vegas Metropolitan Police sergeant Chris Carroll, who was on bicycle patrol at the time of the shooting and was the first officer on the scene that night, told E! News in 2018. "So I asked him, 'What happened? Who shot you? Who did this?' And he was just kind of ignoring me."

Recalling how Shakur was trying to yell at Knight—who was struck in the head by a bullet fragment—but "couldn't' really get a breath together," Caroll continued, "I could just see him going into a relaxed state. And he looked at me and I thought I was actually going to get some cooperation, and he got a breath together and I said, 'Who did this?' He looked at me and he went, 'F--k you.' And that was it."

Since then, there's been many conspiracy theories surrounding Shakur's murder, with the most popular one purporting that his death may be connected to the murder of Christopher "The Notorious B.I.G." Wallace, the East Coast-based rapper who was fatally shot six months later in Los Angeles.

E! News has reached out to Shakur's estate for comment but hasn't heard back.

(E! and NBC News are both part of the NBCUniversal family.)

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