Corey Morgan was found guilty Friday of murdering 9-year-old Tyshawn Lee in 2015.

Morgan, an alleged gang member, stood trial alongside gunman Dwright Boone-Doty, who was found guilty of first-degree murder by another Cook County jury late Thursday night after just three hours of deliberations.

Morgan’s jury, which was sequestered overnight, deliberated for roughly nine hours before reaching a verdict Friday afternoon.

Morgan faces up to 100 years in prison; Boone-Doty faces up to life behind bars.

Morgan showed little reaction as the clerk read off the verdict. The small contingent of Tyshawn’s relatives, who had spent all day Thursday at the courthouse awaiting the verdict in Boone-Doty’s case, did not return Friday to witness the outcome of Morgan’s trial.

Tyshawn’s murder in the fall of 2015 drew national attention after Chicago police revealed that the fourth grader had been targeted by gang members seeking revenge against his father.

Though it was Boone-Doty who lured Tyshawn away from a South Side park and shot him in a nearby alley, prosecutors said Morgan was a key accomplice and architect of the gang feud roiling violence in Auburn Gresham in the months surrounding Tyshawn’s death.

Witnesses testified that Morgan and his fellow Terrordome street gang members declared relatives of their rivals in the Killa Ward gang fair game, after Morgan’s brother was killed and his mother wounded in a shooting carried out by Killa Ward members. Tyshawn’s father, Pierre Stokes, was a reputed high-ranking member of Killa Ward at the time.

The sister of getaway driver, Kevin Edwards, testified that the day after Tracey Morgan was killed, Corey Morgan told Edwards that “everyone must die” in retribution.

“He said ... everybody must die. Grandmas, mamas, kids and all,” Moesha Walker said.

Corey Morgan, who was questioned by police and released days after Tyshawn’s murder, was arrested soon after Walker testified before a grand jury in November 2015.

Defense attorney Todd Pugh told reporters Friday, “Corey Morgan walked into a police station with his head held high. He’s maintained his innocence of this horrible crime since that time and continues to do so.”

Edwards was given a 25-year prison sentence after he pleaded guilty in early September.

State’s Attorney Kim Foxx, in a statement Friday, praised the work of prosecutors and described Tyshawn’s murder as traumatic.

“As a mother and prosecutor, I think often about Tyshawn’s... classmates who returned to school and sat beside an empty desk following this egregious murder and will be graduating eighth grade without their friend on stage later this school year,” the statement read.

Boone-Doty is still awaiting trial for the murder of 19-year-old Briana Jenkins, who was struck by a hail of bullets prosecutors said was intended for a Killa Ward member less than a week after Tracey Morgan was gunned down.

Police traced the .40-caliber pistol that killed Tyshawn to a shipment of guns another brother of Corey Morgan’s purchased from a straw buyer in New Mexico. Anthony Morgan pleaded guilty to federal charges for trafficking guns earlier this year.

The getaway vehicle, a black Ford Edge from a rental car lot at Midway Airport, was found abandoned in south suburban Dolton a few weeks after Tyshawn’s murder. GPS data from the SUV traced a path from Corey Morgan’s house in Lansing to Dawes Park the afternoon Tyshawn was shot, then back to Lansing and later Dolton.

Data from Corey Morgan’s cellphone showed the SUV following a similar route, and the web browser showed that hours after the killing, someone looked up the Facebook profiles of Tyshawn’s mother and father as well as news reports about the murder.

Boone-Doty had been seen by a witness approaching Tyshawn, dribbling the boy’s basketball, and walking with him before the murder. Boone-Doty’s DNA was on the basketball, which investigators found near Tyshawn’s body. Injuries to Tyshawn’s hands showed the boy likely tried to shield his face as Boone-Doty opened fire.

Jurors heard recordings of Boone-Doty bragging about the killing to a jailhouse informant. On the garbled recordings, Boone-Doty boasted that he had no remorse, and even composed a rap about the killing.

Veteran prosecutor Thomas Darman told reporters Friday that he felt his team had a great deal of evidence against Boone-Doty and Corey Morgan, though the facts were sometimes difficult to bear.

“Almost all of us standing here have children, and it takes a toll on everyone,” Darman said. “The toll on us is nothing like the toll it took on Tyshawn’s family and the members of the community.”