CHICAGO — One of two gang members accused in the 2015 execution-style revenge killing of a nine-year-old boy was found guilty of first-degree murder by a jury Thursday night.

Dwright Boone-Doty, 25, and Corey Morgan, 31, were on trial together before two different juries for the murder of Tyshawn Lee. The jury for Boone-Doty, who was the gunman, deliberated for just under three hours before convicting him Thursday.

The jury for Morgan has not yet reached a verdict and will return to deliberations Friday morning after being sequestered overnight following six hours of deliberation.

“While we await the second verdict, we are pleased with the first outcome of this case, knowing that the individual responsible for this heinous, retaliatory attack on a young boy will be held accountable,” said Cook County State’s Attorney Kim Foxx in a statement.

“We hope that this verdict brings some measure of closure and peace for the family of Tyshawn Lee, whom we will never forget,” she added.

Prosecutors presented evidence during the duo’s nearly three week long trial that showed the two had planned the fourth grader’s murder as revenge after Morgan’s brother, who was also a gang member, was killed and his mother wounded in a violent encounter that may have involved the boy’s father who was part of a rival gang.

“Morgan wanted revenge,” prosecutor Margaret Hillmann said in her opening statements during the murder trial which started on September 17. “He was in a murderous rage, saying he was going to kill grandmas, mammas, kids and whoever he could catch.”

Prosecutors described to the jury how one of the men approached the fourth-grader while he sat on a swing at a park after school on the city’s South Side.

Boone-Doty struck up a conversation with Tyshawn and eventually convinced the boy to follow him to a nearby alley under the guise of buying him a snack while Morgan watched from a parked car that prosecutors pinned to the park through GPS evidence.

After luring him there, Boone-Doty shot the boy point-blank multiple times and left him to die, prosecutors said.

“The last thing he saw was this guy pulling out his gun and firing repeatedly from close range as he tried in vain to defend himself, ” prosecutor Patrick Waller said during his closing statement.

The deliberate targeting of the young boy horrified not only the larger community but several gang members who said the act was unheard of, even on the streets, because it broke an unspoken code to keep unaffiliated family members out of gang wars.

One of the more damming pieces of evidence presented at trial was a taped recording where Boone-Doty allegedly confessed to the boy’s killing in a boastful manner to a fellow inmate who was working with police as an informant at Cook County jail.

“You ain’t never stepped back and thought, damn, I shouldn’t have did that?” asked the informant on the recording.

“No, I don’t got that in my head, not even a little bit,” Boone-Doty replied. “Ain’t no age. Period. Age 8 to 80,” he said, according to the Chicago Tribune. “Eight days, eight seconds in this world, or 80 years, this is what I’m telling you.”

Boone-Doty went on to describe the scene including the gun shots in more detail. “I’m looking at him. We walking. Bop. Hit the ground. Bop-bop-bop-bop-bop. I’m laughing. I’m looking … Bop bop bop bop bop man.”

The informant told authorities that Boone-Doty even wrote a rap song about killing the boy who he referred to as “Shorty.”

Defense attorneys cautioned jurors to be skeptical of the recordings and credibility of the informant, and added that Boone-Doty said those words because he had to uphold a tough image of himself to survive in prison.

Prosecutors also called a county forensic pathologist who testified that Tyshawn was shot in the head, twice in the right hand, and also suffered a graze wound to the back — all in close range. Part of his right thumb had been blown off by a bullet when he raised his hands to block the shots.

Defense teams for both men tried to lessen the impact of each of their client’s actions by pinning more culpability on the other man.

An attorney for Boone-Doty argued that there were no witnesses to the shooting and that police hastily arrested her client without a proper investigation.

After the boy’s murder, an already intense gang feud on the city’s South Side exploded with a series of retaliatory shootings. The boy’s father, Pierre Stokes, allegedly shot Morgan’s girlfriend and two others the same day prosecutors revealed new details in court about Tyshawn’s execution-style killing, including allegations that the gunman had considered torturing the boy by cutting off his fingers and ears, according to the Chicago Tribune.

Tyshawn’s family members, including his grandmother who was the last relative to see him before he went to the park, described his final moments in gut-wrenching testimony.

“He said, ‘I’ll be back.’ He didn’t come back,” testified an emotional Bertha Lee.

Boone-Doty faces a potential life sentence.