Last October, Dwright Boone-Doty and Corey Morgan were both convicted by separate juries in the fatal shooting of Tyshawn.
RELATED: Jury finds second man guilty in fatal shooting of 9-year-old Tyshawn Lee
Prosecutors said the two men lured Lee into a South Side alley near Dawes Park and that Boone-Doty shot the boy at close range, while Morgan watched in a nearby getaway car with a third man.
Prosecutors claimed that Boone-Doty and Morgan targeted Tyshawn as part of an escalating gang feud. They allegedly believed a gang linked to the boy's father was responsible for killing Morgan's brother a few weeks earlier and wounding his mother, according to prosecutors.
Boone-Doty was sentenced to 90 years, without a chance of parole. Morgan was sentenced to 65 years,.
"I've been waiting for this day for four years," said Karla Lee, Tyshawn's mother. "I'm happy. My son got what he deserved. It's justice."
On Wednesday, Cook County State's Attorney Kim Foxx said the case "has rocked all of us in the city and around the nation with it's heinous nature."
WATCH Cook County State's Attorney Kim Foxx speaks after 2 men sentenced in 2015 murder of 9-year-old Tyshawn Lee
Defense attorneys said Morgan and Boone-Doty are victims of their upbringing. They were raised in the same neighborhood without fathers. Their attorneys argued for minimum sentences.
Morgan's attorney Thomas Breen said, "There is no purpose, not one purpose has been served by the killing of Tyshawn Lee. Nothing. Lives have been destroyed. Lives will now be spent behind bars and for what?"
Judge Thaddeus Wilson said there is no excuse for the crime, calling it debilitating, mind-numbing violence.
When Wilson asked the defendants if they wanted to address the court, each man declined.
Tyshawn's family said the murder has changed their lives forever.
"We just try to move forward," said Teresa Wilson, Tyshawn's grandmother.