Robert Serritella, accused Skokie child killer, linked to other sex attacks

CHICAGO (WLS) -- There are troubling new details in a case the I-Team has been investigating for more than 20 years. An accused suburban child killer has now been linked to at least six sex attacks - both before and after the murder of 15-year-old David Chereck.

Years after David Chereck was strangled with his own scarf, Robert Serritella was arrested and charged with the teenager's murder. On Tuesday, prosecutors said there is more to it - a horrible backstory.

Serritella had others victims of his sexual perversion, they say, boys and young men he had stalked and molested, but not killed. And now, authorities say they want to call those victims as witnesses during Serritella's murder trial.

"I had a good description of the boy and the driver," Serritella said in 1998.

WATCH: I-Team's original coverage of David Chereck murder

READ: Motion to present evidence of other crimes in Serritella case

In interviews with the I-Team over the years, Robert Serritella described specific details of the murder and even placed himself at the crime scene. On January 1, 1992, New Year's night, 15-year-old Skokie teenager David Chereck had just left some friends and was walking home. He never made it.

The teenager's body was found in a Cook County forest preserve. Last summer, more than two decades later, Serritella was arrested.

"I did not kill this boy. I did not kill this boy. I did not kill this boy. Everything is circumstantial," Serritella said in September 2014.

On Tuesday in criminal court, county prosecutors revealed for the first time that Serritella had a "propensity as a child sex offender."

They filed a lengthy motion stating that he had stalked at least six young men as young as 14 - before and after the Chereck murder - and now prosecutors say want those victims of Serritella's similar, but uncharged crimes, to testify about what happened.

Attorneys for the 72-year-old Serritella say they will fight the use of witnesses from uncharged cases. A hearing is now set for April.

Prosecutors also disclosed a motive for the first time on Tuesday. In court records, they say that Serritella "killed David Chereck to silence him... to destroy any evidence of the abduction and sexual assault."

Those six-newly claimed sexual assault victims escaped with their lives, although prosecutors say Serritella tried to run over one victim with his car but failed.