The question remains over who shot Notorious B.I.G.? and that is the biggest issue that Johnny Depp and Forest Whitaker will try to solve in their upcoming movie, “City of Lies.” which the trailer was released today.

Depp plays LAPD’s detective Russell Poole, whose has often been portrayed in many movies as the real-life officer who investigated the death of Christopher Wallace better known by his stage name as Biggie, who was killed in a drive-by shooting in 1997, shortly after his west coast peer, Tupac Shakur was murder.

The movie sees him teaming up with reporter Jack Jackson played by Forest Whitaker, a character inspired by Randall Sullivan, who wrote the book “Labyrinth” on which the movie is based.

“A murder like that only goes unsolved if the police don’t want to solve it,” Depp’s Poole says in the trailer, while warning that if a connection between cops and the murder was ever unearthed, “it would ruin the city.”

Here’s the official synopsis for the movie, hitting theaters September 7:

Based on the true story of one of the most notorious and unsolved cases in recent time, CITY OF LIES is a provocative thriller revealing a never-before-seen look at the infamous murder of The Notorious B.I.G. shortly following the death of Tupac. L.A.P.D. detective Russell Poole (Johnny Depp) has spent years trying to solve his biggest case, but after two decades, the investigation remains open. “Jack” Jackson (Forest Whitaker), a reporter desperate to save his reputation and career, is determined to find out why. In search of the truth, the two team up and unravel a growing web of institutional corruption and lies. Relentless in their hunt, these two determined men threaten to uncover the conspiracy and crack the foundation of the L.A.P.D. and an entire city.