On Wednesday, two 15-year-olds were biking south on Terra Cotta Road, near the intersection of Deering Oaks Lane in unincorporated Crystal Lake, just after 9:30 p.m., when a car hit one of the bikers from behind, the McHenry County Sheriff's Office said.
The vehicle kept driving, the sheriff's office said.
Nick Laureys, 15, died from his injuries at the hospital, his family said.
Police said he did have a red taillight that was activated on his bike, police said.
The sheriff's office said the vehicle involved may have been a dark-colored red 2017-2018 Jeep Cherokee.
On Friday, Woodstock police said they found a matching vehicle during a death investigation at a home.
The dead person found in the home was identified as the suspect of the deadly hit-and-run crash, the sheriff said.
Officials have not released the suspect's name.
Police are not looking for more suspects.