Police say Cecil R. Conner, 22, had a blood alcohol level three times the legal limit when he crashed into a tree in south suburban Steger.
Conner has been charged with felony DUI and reckless homicide in the crash at West 34th and Carpenter streets at 3:15 a.m. Monday. He struck several trees, police said, before the vehicle came to rest.
Conner was not hurt, but his girlfriend's son, Michael Langford, 5, died instantly. The child was riding in a booster seat, police said.
"We came over to the car, found the driver still in the vehicle and he was positioned to where he was talking to the child in the backseat. I could see the child was not responding," said Sgt. Gerald Ruff, Steger Police Department.
"The only question is, 'Why is he here?' Whenever anybody gets killed in a situation like that, it's tragic and our condolences go out to the family of the child. And it's alcohol," said Chief Richard Stultz, Steger Police Dept.
According to a family friend, Conner and his girlfriend, Kathie Lafond, were at a friend's house until early Monday morning.
"They had a few drinks. They ended up leaving. We made sure Kathie drove because she was the designated driver," said Dane D'Andrea, driver's friend.
About 45 minutes later, Lafond was pulled over by Chicago Heights police for making an improper turn. When they discovered she was driving without a license, Lafond was taken into custody and the keys to the car were given to Conner.
"The officer did not see visible impairment nor smell alcohol on the person's breath. He had the subject out of the car speaking to him. He observed him walk to the driver's side of the vehicle to take control," said Chief Michael Camilli, Chicago Heights Police Department.
The Chicago Heights Police Department is conducting an investigation into the police officer's actions.
Lafond's family said they saw the boy last on Sunday during a Mother's Day celebration.
"I love him so much. I wish nothing happened to him," said Stephanie Lafond, victim's cousin.
"He was a good little boy. He made me laugh all the time," said Krystal Lafond, victim's cousin.
Chief Stultz said Conner spent several hours passed out at in the lockup and is not coherent enough to give a statement. He does not know the boy is dead, Chief Stultz said.
Conner is expected to be in bond court Tuesday at the earliest.