Police would not release details in this second case, but said the sexual assault happened several years after the kidnapping and murder of Maria Ridulph, 7. Ridulph's body was found five months after she disappeared from her Sycamore home in 1957. Her body was recently exhumed to help in the investigation following the arrest of McCullough in July.
He is being held on $3 million bail in the Ridulph murder.
According to the Illinois State Police and DeKalb County State's Attorney's Office, the victim told police she was raped by McCullough when she was 14 years old. She also lived in Sycamore at that time.
"Sadly, we have another victim, and for the families of all victims, the pain never goes away," said ISP Director Hiram Grau in a statement. "The ISP Special Agents who have been tirelessly working this case will continue to be unrelenting in their efforts to find justice, closure, and peace for the Sycamore community."
McCullough also goes by the name John Tessier.