Kevin C. Jarrett, who went by K.C., arranged the sale using an app called LetGo, where people can buy and sell items second-hand. But instead of making the sale, the 31-year-old man was robbed and then shot to death.
"If someone wanted to sell something online, you just make the transaction and go about your day, but obviously something went wrong," said Jakayla Purnell, Jarrett's niece.
The search is on for his killer. Police said three suspects may be involved in the crime.
Jarrett was shot around 10:45 p.m. in the 800-block of White Oak Lane, where rows of townhomes line a tucked-away subdivision.
"I just heard the little pow-pow type stuff, the normal stuff. We just thought it was fireworks," said Tamieka Smith, a neighbor.
"That's so scary. That's so close to our house. It makes you not want to buy online," said Nicki Smith, who also lives nearby.
Police said Jarrett was with a his girlfriend when he was shot, but she wasn't harmed. She drove him away down White Oak Lane, but the car stopped a couple of blocks away at Burnham Drive, police said. Jarrett later died. Jarrett's girlfriend is cooperating with the police investigation.
"We're currently working with LetGo.com and trying to locate the victim's account and try to trace back the steps of the transaction," University Park Police Chief John Pate said.
Jarrett's family said he was a family man. He had three kids and worked with his father every day at a seasoning company in Momence, Ill. He loved video games. Relatives said they can't understand why he would drive to University Park to make any kind of sale.
"It is very, very, very unusual, due to the circumstances. Why would he sell this Xbox that I heard of, and he just got paid yesterday? So, it's so much more and so many unanswered questions, when all he do was play the games, be with his cousins, and his family and his son. He's not even familiar with that area. We don't have family in that area. Nothing," the victim's sister, LaShonda Jarrett, said over the phone.
"Nobody wanted to hurt him," said Craig Dorsey, Jarrett's cousin. "He wasn't into it with anybody."
The suspect descriptions released by investigators were very vague. A witness told police they saw three people wearing all black. One of them was described as a juvenile, wearing his hair in an Afro.
Anyone with information on the shooting should go to the University Park Department or call (708) 235-4803.
The Sun-Times Media Wire contributed to this report.