Will County State's Attorney James Glasgow called Vaughn a "sociopath" after the verdict, which came after more than 7 hours of closing arguments, the (Joliet) Herald-News reported.
"He's a psychopath. He's going to get life in prison," Glasgow said. "And after that he's on his road to perdition."
Vaughn is scheduled to be sentenced Nov. 26.
Notable deaths of 2014 [PHOTOS]