Cook County's chief prosecutor has revealed details of how

Cook County's chief prosecutor has revealed details of how she says a gang member lured a 9-year-old Chicago boy from a playground into an alley and then killed him in an act of retaliation against the boy's father.

State's Attorney Anita Alvarez told reporters Tuesday that Tyshawn Lee was playing on the swings Nov. 2 when Dwright Boone-Doty approached him. She says Boone-Doty dribbled the boy's basketball a few times, gave it back to him and offered to buy him whatever he wanted from a store.Alvarez says they walked off into an alley where Boone-Doty shot the boy several times.

The 22-year-old man was charged Monday with first-degree murder. The Cook County State's Attorney's office says Boone-Doty also is charged with murder in the shooting death of 19-year-old Brianna Jenkins on Oct. 18. London has fallen

John Escalante, interim police superintendent, said Tuesday morning that Tyshawn Lee's death was the culmination of gang violence that spiraled into retaliation and "zero regard for human life." WGN reports that Alvarez said Doty first wanted to torture the boy by cutting off his fingers and ears.

Assistant State's Attorney George Canellia said Doty laughed as he described to another inmate how he shot Lee in the head, reports WGN.

Guglielmi says Boone-Doty was held on unrelated gun charges when investigators connected him with Tyshawn's death.