(CNN) On a warm and sunny afternoon in November 2015, 9-year-old Tyshawn Lee was still in his school uniform when he told his grandmother he loved her and raced across the street to a Chicago park with his basketball.

Two of three men accused of killing the fourth-grader in a case that shocked the city were waiting for him, prosecutor Margaret Hillmann said during opening statements in their trial on Tuesday. They were armed and ready to lure the boy to his death in what Hillmann said was a revenge killing meant to settle a gang feud.

The defendants, Dwright Doty and Corey Morgan, are being tried together but before separate juries.

The getaway driver, Kevin Edwards, pleaded guilty this month in exchange for a 25-year sentence, CNN affiliate WLS-TV reported. In August, Morgan's brother, Anthony, was sentenced to four years in prison for buying the gun used to kill Tyshawn.

Hillmann said Doty and Morgan, reputed members of the Black P. Stone Nation Bang Bang Gang, or BBGs, that day were looking to exact revenge for the killing of Morgan's brother and wounding of his mother one month earlier by members of the rival Gangster Disciples Killa Ward group.

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