Chicago area teens have been charged with the brutal murder of a former friend, who was stabbed, run over with a car, and then burned alive, police said.

The burned body of local teenager Luis Guerrero was discovered on August 14 during what was to have been a training exercise by firefighters in the suburban town of West Chicago. The exercise turned into a murder investigation once the smoldering body was discovered, CBS Channel 2 reported.

“Towards the end of the training, they saw some smoldering off the side. I went over and checked it out. They found the body,” West Chicago Police Chief Michael Uplegger told the media:

West Chicago police investigating the death of an adult found burned in a home on 1300 block of Joliet. @cbschicago pic.twitter.com/vtNnmLQE2c — Charlie De Mar (@CharlieDeMar) August 15, 2018

A neighbor told police a truck was seen leaving the area early in the morning on August 14.

The body was later identified, and after an investigation, police arrested three teens; 18-year-old Francisco Alvarado and 16-year-old Tia Brewer, the victim’s former girlfriend, were charged with murder. Jesus Correa, 18, was charged with concealment of a homicide. Some of the victim’s belongings were found in Brewer and Alvarado’s possessions, police added.

An investigation reportedly revealed that Brewer met the victim in a local library, then enticed him to leave with her and the two other suspects. While in a Jeep Cherokee, police said, Guerrero was strangled with a belt and stabbed several times in the neck. The victim was then driven to the field where his body was later found.

Police reported that once at the field, Guerrero was thrown to the ground, doused in gasoline, and set aflame while still alive. He tried to run, but the three assailants chased him down and ran over him with the automobile. He was again beaten, doused with more gas, and set on fire a second time, according to police.

Investigators said there was a lot of blood evidence inside and underneath the car.

After her arrest, Brewer said Guerrero had raped her and that his murder was retaliation for the attack. But police have no report of any sexual assault involving either Guerrero or Brewer.

The three suspects will next appear in court on September 13. Alvarado and Brewer face life in prison if convicted.

Follow Warner Todd Huston on Twitter @warnerthuston.