Rudy Rangel Jr. liked to keep his hair short. So Rangel, a leader of the Latin Kings, one of Chicago’s biggest street gangs, had been going several times a month to Nationwide Cutz, a barbershop operating out of a trailer near Roosevelt and Sacramento on the West Side.

On June 4, 2003, late in the evening, the gang leader known as “Kato” was in the barber chair, his back to the open door, Game 1 of the NBA Finals between the San Antonio Spurs and New Jersey Nets on the TV.

Outside, a 21-year-old, recently paroled ex-con named Donell “Squeaky” Simmons walked through the alley to the shop, a red, white and blue Nets cap on his head and a pistol at his waist.

Two men were sitting on the stairs to the barbershop, waiting to get in, when Simmons walked up. “Let me get by,” Simmons told them.

In a few moments, Rangel, 30, lay dying.

Now, 15 years later, 11 members of the Four Corner Hustlers, including Labar “Bro Man” Spann, leader of the gang, await prosecution next year in one of the biggest gang trials ever in Chicago. Rangel’s killing and five other murders are at the heart of the sweeping racketeering conspiracy case set to be heard in federal court in September 2019.

Though Simmons and two others went to prison in Rangel’s death, some details of the high-profile killing — rapper DMX later recorded a tribute to Rangel called “A’Yo Kato” — never came out.

Authorities said the shooting resulted from an attempted jewel robbery. But interviews and thousands of pages of records from the U.S. attorney’s office, the Chicago Police Department, the Cook County state’s attorney’s office and the Cook County medical examiner’s office reviewed by the Chicago Sun-Times suggest another possible motive: that the murder was contracted after Rangel stole 150 kilos of cocaine. Based on those records.