Plot

Russell Poole and Jack Jackson investigate the murder of rapper Notorious B.I.G.

1997. LAPD Detective Russell Poole investigates a case of an undercover cop killing another cop. This draws him into the Biggie Smalls and Tupac Shakur murders. What he uncovers is huge, so much so, that the closer he gets to the truth, the more his superiors try to prevent him from getting to it.—grantss

The 90's is the decade of violence by white cops against black people which goes unchecked in the courts. The film tells the story of American hero and former LAPD detective, Russell Poole (Johnny Depp), who in 1997 is working the murder cases of rappers Tupac Shakur and The Notorious B.I.G..

In 2017, A reporter (based on journalist Randall Sullivan's collaboration with Russell Poole), "Jack" Jackson (Forest Whitaker), teams up with Poole after nearly two decades to find out the truth. Jack discusses with Poole that back in 1997 Tupac and BIG were churning out songs about how black lives were being snuffed out by white caps. Tupac was active on East coast and BIG was active on the west coast. BIG was shot by unknown assailants when he was driving out in his car after a late night concert.

In 1997, Poole was investigating the death of a black cop Kevin Gaines (Amin Joseph) by a white cop Detective Frank Lyga (Shea Whigham). Both were driving cars and ended up at the same junction and both were undercover and didn't know each other. Frank, said something racist, Kevin reacted and Frank shot Kevin. Frank claims that Kevin attacked him first and that he tried to drive away. When Kevin didn't relent, he shot Kevin in self defense.

Poole meets BIG's wife who claims that Kevin was working for BIG providing security and knew something for which he was shot. Word was that BIG was shot on orders by Sugar Night, the producer of Tupac's records & associated with the drug gang Deathrow. Dreadlocks (Rockmond Dunbar) is an undercover FBI agent who meets Poole. He tells Poole that Sugar Night had LAPD in his right pocket. Lieutenant O'Shea (Dayton Callie) wants Poole to declare Frank not-guilty and move on, but Poole refuses unless he investigates thoroughly. So O'Shea moves Poole to the Homicide division and assigns Detective Fred Miller (Toby Huss) as his partner. Miller gets an informant who tells that somebody called D Mack gave out a contract for killing BIG.

Meanwhile Poole also figures that in LA Tupac was shot and the finger pointed to a contract taken out by BIG (some sort of east vs west rivalry). Sugar Night was devastated by Tupac's death and hence took the contract out on BIG. At this point Poole shares his theory with Miller that Kevin Gaines was involved in the shooting of BIG. The next day Kevin's family sues LAPD for 25 MM USD. D Mack turns out to be David "D. Mack" Mack (Shamier Anderson), who collaborated with his cashier girlfriend to rob the vault of a local bank. Miller and Poole arrest David and at his apartment they find all the evidence that shows that David or D Mack actually carried out the shooting to kill BIG.

To make matters worse, if David and Kevin are convicted in the shooting of BIG, then Kevin's family's lawsuit would end up bankrupting the city of LAPD. Basically Poole had unearthed evidence that LAPD officers had a history of working for Deathrow gang. Jack confronts current police Commander Fasulo (Peter Greene) and asks why the LAPD never solved the BIG and Tupac murders even in light of overwhelming evidence. Fasulo tells Jack that Poole was suspended and is mentally unstable. Another theory was that an Islamist by the name of Amir Mohammed had killed BIG.

Jack cant believe this and meets Miller, who says that Poole was the best detective ever. Miller also tells Jack that while D Mack was in jail, he only ever got one visitor, Amir Mohammed. Miller tells Jack that every-time Poole tried to make progress he was impeded by O'Shea. So Poole went to the COmmissioner of Police, which earned a rebuke from O'Shea. So, Poole filed a complaint against the LAPD. Rafael Pérez (Neil Brown Jr.) was another corrupt LAPD cop who blew USD 25 K in Las Vegas 2 days after the D Mack Bank robbery. He was also stealing drugs from the LAPD evidence room and giving it to Frank for street distribution. Poole starts trailing Perez and actually witnesses him commit a murder (he killed a drug distributor to rob him off the money). Perez was put on trial and admitted to 70 other LAPD cops being corrupt. But Poole reveals to Jack that this was just a diversion as it took attention away from the BIG Tupac investigations.

When Kevin's family case against LAPD went to trial, the judge ordered a mistrial as he found evidence of LAPD hiding material facts. In response, the LAPD re-opened the investigation, as one cannot sue anyone while the investigation is "open". Poole finally gets the courage to type up his theory and takes it to the homicide dept. As he hands in his report, he gets a heart attack and dies.