The 18-year-old man was shot at about 9 p.m. in the 2800 block of West Arthington Avenue, sustaining wounds to his neck, buttocks and groin, police said. He was one of 10 people to be shot Friday night and Saturday.
The newspapers reported the man is the lone suspect in the slayings of 31-year-old Chavonne Brown and her son, Sterling Sims, 5. Police were called to the 5300 block of South Winchester Avenue about 2:39 a.m. Friday, where they found the bodies of Brown and Sterling.
On Saturday, family members declined to talk to a DNAinfo.com Chicago reporter.
Two other people were in the home at the time of the shooting, including Sterling's 11-year-old, according to family.
Steve Sims, the slain boy's father, said Friday afternoon he knows who killed his son and ex-girlfriend.
"He wasn't a stranger. He knew them," Sims said. "She let him in, and he had bad intentions."
Sims and neighbors said Brown had been letting a man stay with her after the man's family had "turned their backs on him." They said the man had plans to kill all four people who were in the house, but his gun jammed after shooting Brown and Sterling.
Sims sat on a plastic crate as friends came by to offer their condolences. He said his son was a "charismatic" kid who "had his whole life ahead of him."
"He loved everybody. He was open to everything," Sims said. "If he didn't know you, [he'd] see you one time, the next time he'd see you, he'd come up and hug you."
Sims said Sterling had just graduated kindergarten at Henderson Elementary two weeks ago and was mad school had ended because he "wanted to keep seeing his friends."
"He loved school," Sims said.
Friends described Brown, who babysat for a living, as generous and willing to take people in who were having a hard time.
"She was a loving person," said Ferneacres Smith, a 36-year-old cousin of Brown. "She gave you her heart."
Friday morning, Smith asked whoever is responsible for killing Brown and Sterling to come forward.
"You took something from us we cannot get back," she said. "You took two precious lives."
Veronica Smith, a friend and neighbor of Brown, said she was introduced to her when she first moved into the neighborhood.
"She welcomed me with open arms," Smith said. "She was a great mother. Every day, all day."
Smith said Brown liked to laugh, and she'd sit on the porch with her two boys. She said Sterling would play basketball with her own son, who was like another big brother to the 5-year-old.
Smith said she heard the gunshots in Brown's home overnight Thursday. On Friday morning, she was inside the house helping to clean it.
"I'm seeing things that no one should have to see," she said. "A waste of life."