By Charlie De Mar

CHICAGO (CBS/AP) — A jury convicted one of two defendants of first-degree murder Thursday evening in the 2015 killing of a 9-year-old Chicago boy who was allegedly lured to his death by being promised a juice box.

Dwright Boone-Doty was seen smirking at times as the jury read his guilty verdict in the murder of Tyshawn Lee. Boone-Doty was also seen shaking his head as the verdict was read.

The verdict closes one chapter in the revenge killing of the 9-year-old.

As CBS 2’s Charlie De Mar reported, it took the jury just about three hours to convict Boone-Doty. It was a case with seemingly overwhelming evidence that struck a chord with Chicagoans and beyond.

Prosecutors called it a calculated execution of a 9-year-old.

“Even at a time when we’ve become nearly numb to headlines about violence, this case shook us to our core.” said Cook County State’s Attorney Kim Foxx said in a news release. “We grieve for nine-year-old Tyshawn as we continue to hold close those who are laboring in his wake. As a mother and prosecutor, I think often about Tyshawn’s 4th grade classmates who returned to school and sat beside an empty desk following this egregious murder and will be graduating 8th grade without their friend on stage later this school year. The trauma is far-reaching and impacts us all, collectively.”

Tyshawn Lee, 9, was fatally shot in the Gresham neighborhood. (Courtesy: Karla Lee)

The decision brought joy for some, who were seen hugging outside the courthouse.

During the trial, it was revealed that Boone-Doty’s DNA was found on a basketball that was located feet from Tyshawn’s body, and also inside a sport-utility vehicle that was used as a getaway car.

There were also powerful recordings from a jailhouse informant that were played for the jury. Boone-Doty could be heard bragging about killing the fourth-grader and even laughing.

Prosecutors have said Boone-Doty and co-defendant Corey Morgan plotted to kill the fourth grader because his father was a member of a rival gang they suspected of killing Morgan’s brother weeks earlier.

Police and prosecutors said both shootings stemmed from an ongoing gang war between the Terror Dome faction of the Black P-Stones and the Killa Ward faction of the Gangster Disciples.

Morgan and Boone-Doty spotted Tyshawn playing basketball at Dawes Park at 80th Street and Damen Avenue on Nov. 2, 2015, according to police and prosecutors.

Tyshawn Lee, 9, was fatally shot in the Gresham neighborhood. (Courtesy: Karla Lee) (Photo supplied to CBS)

Tyshawn put down his basketball and began playing on the swings at the park, and Boone-Doty walked up to him and offered to take him to the store and buy him anything he wanted, prosecutors said. Boone-Doty then allegedly lured Tyshawn into a nearby alley, where he allegedly shot Tyshawn multiple times at close range.

Authorities have said Boone-Doty admitted his role in Tyshawn’s death and said when he shot the boy, he “seen that bitch go in his head.”

“This was a targeted assassination,” acting Chicago Police Supt. John Escalante said at the time. “These are calculated killers whose actions define the words brutality and cowardice.”

Morgan’s trial is being heard by a separate jury. That jury has not reached a verdict and called it a night for the night Thursday. Their deliberations will resume Friday morning.

The Morgan jury is sequestered and is not aware of the guilty verdict against Boone-Doty.

A third man, 26-year-old Kevin Edwards, has pleaded guilty in exchange for a 25-year sentence. Prosecutors have said he was the getaway driver in Tyshawn’s slaying.

On the day Boone-Doty first appeared in court accused of killing Tyshawn, the boy’s father, Pierre Stokes, allegedly opened fire on gang rivals, wounding three of them, authorities have said. Stokes is in jail awaiting trial on aggravated battery and other charges in that attack.

(© Copyright 2019 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)

Charlie De Mar