CHICAGO — After just a few hours of deliberation late Thursday night, a Cook County jury found a man guilty of first degree murder of Tyshawn Lee, a 9-year-old boy who was shot and killed in one of Chicago's most horrific crimes.

Jurors found Dwright Boone-Doty guilty of murder in the first degree for shooting the boy in the head after promising to buy him a treat. Boone-Doty led the boy into an alley and executed him in a gang hit that shocked the nation for its brutality.

Boone-Doty and another man, Corey Morgan, were tried before separate juries. Morgan's jury was still deliberating as of Thursday night.

Several members of the boy's family held hands as the court read the verdict. Upon hearing the verdict, they began crying.

A third man involved in the murder, Kevin Edwards, has already pleaded guilty to first-degree murder in exchange for a 25-year prison sentence.

“Tyshawn Lee’s life is over, way too short. Although his life is over, his story isn’t," state's attorney Craig Ingleford told the jury earlier in the day during closing arguments. "It’s an ending you get to write. It will never be a happy ending, but it can be a just one.”

Tyshawn was a fourth grader in November 2015 when he was killed by gang members to send a message to his father, an alleged member of a rival gang, prosecutors say. The killing was seen by many as underscoring the viciousness of warring factions in Chicago.

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Over the past two and a half weeks, the jury has borne witness to the horrifying details of the child's execution-style murder, with testimony ranging from police to family members.

After school on Nov. 2, 2015, Tyshawn was sitting on a swing at the park down the street from his grandmother's house when a man approached him, dribbled his basketball, offered to buy him a snack and then led him to an alley, where he shot the child several times at close range, prosecutors say.

The execution-style shooting was an act of revenge, according to prosecutors. Boone-Doty and Morgan, members of the same gang, believed that a rival faction had killed Morgan's 25-year-old brother and wounded his mother a month earlier.

Morgan and Boone-Doty were angered by the attack and wanted to get back at Tyshawn's father, Pierre Stokes, who was also an alleged member of the rival gang, prosecutors say. So Boone-Doty struck up a conversation with Tyshawn and led him to the alley.

Shell casings at the scene of the crime and the associated gun would eventually be linked back to Morgan and his brother, Anthony Morgan, who purchased the gun from a man in New Mexico.

A major moment in the case came last week, when a witness revealed how officers first recovered the weapon used to murder Tyshawn: In 2017, a squad car pulled up on an empty lot where a rap video was being filmed, causing "several dozen people" to flee the scene, leaving behind five guns, according to Sun-Times reporting. One of those guns was linked to Tyshawn's murder.

The revelation angered Morgan's lawyers, who wondered why individuals involved with the video were not brought in for questioning. On Thursday, Cook County Circuit Judge Thaddeus Wilson said that the new information did not merit a mistrial.

The final week of testimony packed a punch.

On Monday, jurors heard recordings of Boone-Doty from 2015 bragging about the murder to a jailhouse informant, who was secretly wearing a wire. In the recording, Boone-Doty can be heard rehashing how he lured Tyshawn into the alley and laughing about how he shot the boy.

Boone-Doty's attorney argued that the defendant didn't really mean what he had said —that he was only putting on a front to look tough in jail.

On Wednesday, prosecutors revealed graphic images of the boy's autopsy, including images of bullet wounds to Tyshawn's head and hands.

Cook County medical examiner Dr. Ponni Arunkumar testified that the manner of death was homicide, caused by multiple gunshots wounds.

About a dozen of Tyshawn's family members and supporters were present in the fourth-floor courtroom for closing arguments Thursday.

In the morning, prosecutors reiterated the evidence against Corey Morgan and replayed a clip of one key eye-witness identifying him. The prosecution based its argument on eyewitness testimony, GPS tracking in the car that Edwards drove, Morgan's cell phone records, DNA evidence found in the car and on Tyshawn's basketball, and more. Ingleford again made the case for Morgan's motive: His family had been attacked, and he wanted revenge.

At one point, the prosecution briefly showed two images of Tyshawn's small body crumpled on the ground in the alley where he was shot.

Morgan's lawyer Todd Pugh presented the defense's closing argument, saying that Morgan had been improperly identified, and that Chicago police had not explored other potential suspects.

Pugh labeled the prosecution's argument a “wonderful presentation," but called it a “pivot” that "bends the evidence." He encouraged the jury to consider the credibility of "coerced" witnesses and said several police lineups had not been conducted properly, to Morgan's detriment.

Pugh told the jury not to let the tragedy of the case or prejudice against gang members lower the burden of proof.

"You know, if Corey Morgan had been somebody different, the investigation would have been different. In the eyes of the police, he’s one of those throwaway people," Pew said.

The defense honed in on one of the eye-witness identification, saying that the witness was shown photos of the defendants before the official ID process began, prompting him to identify Morgan. The defense also pointed to GPS information to show that the timeline of the afternoon that the witness presented was "just not possible."

Pugh highlighted the testimony of one witness who did not see Morgan or Boone-Doty at the park.

In his rebuttal, Assistant State's Attorney Patrick Waller said the defense was placing blame on Chicago police and making them a "scapegoat."

He responded directly to Pugh's characterization of Morgan as a "throwaway person."

“Well you know whose life was thrown away by this defendant and his compatriots?" Waller asked. "Tyshawn Lee. They threw his life away.”

As the jury in Morgan's case was still deliberating Thursday afternoon, the court heard closing arguments in Boone-Doty's case.

The prosecution detailed how probabilistic genotyping had linked Boone-Doty to DNA found on Tyshawn's basketball. In situations where DNA evidence is of low quality or comes from a mixture of different sources, probablistic genotyping software offers scientists a way to statistically determine how much that DNA evidence should be weighed.

The prosecution then re-played the audio of Boone-Doty bragging and laughing about shooting Tyshawn.

“This is someone without an ounce of remorse,” Waller said.

After hearing the audio, one family member had to step outside the courtroom.

The defense opened its closing arguments with a recognition of the horror of Tyshawn's murder.

“What does someone say to a jury when they’ve sat through three weeks of testimony about the murder of a 9-year-old child?” asked Boone-Doty's lawyer Danita Ivory.

Ivory critiqued the way that Chicago police had collected witnesses and conducted lineups. Ivory said one key eye-witness only identified Boone-Doty after requesting a reward. She said that the science behind probablistic genotyping was suspect and could not definitively link Boone-Doty to the murder.

“You can have all the sympathies in the world for Tyshawn…but justice doesn’t say you convict for the sake of conviction," Ivory said. "Justice does not mean convicting the wrong person."