Oswego resident Vaughn was convicted of killing his wife and three children. His sentencing had been scheduled for Monday but is delayed as the judge considers the defense motion for a new trial.
Vaughn defense attorney George Lenard has a very unique argument: He says that attorneys for Drew Peterson were so obnoxious that they biased the jury deciding his client's fate as the two men were on trial at the same time in neighboring courtrooms.
ABC7 spoke to Lenard as he left court after spending the day trying to convince a judge that his client didn't get a fair trial.
Does he think his argument for a retrial is a tough sell?
"I don't think so," Lenard said.
A jury found Vaughn guilty of the June 14, 2007, murders of his wife Kimberly and their three children in the family's SUV during what was supposed to be a trip to a Springfield waterpark.
In court Monday, defense attorney Lenard cited 51 grounds for a new trial, blaming the negative impact of the Drew Peterson case and the intense media attention it brought to both trials.
Prosecutors did not make any comment.
But, assistant Will County state's attorney Michael Fitzgerald told the judge, "It's unbelievable the Drew Peterson case would find itself in the Christopher Vaughn case."
Lenard also accused prosecutors of damaging his credibility with the jury and their ability to consider his client's explanation for the crime, that a suicidal Kimberly Vaughn killed her kids, shot her husband and then turned the gun on herself.
"I don't know exactly what it is that they were thinking, but 45 minutes and not asking for any exhibits, not wanting to hear any testimony that's extremely rare," said Lenard. "I've never had that situation before, and that's odd."
Vaughn faces a mandatory life sentence.
Both the families of Christopher Vaughn and Kimberly Vaughn were in court. They left court without comment.
The judge said he would rule on the motion for a new trial Tuesday morning then proceed with the sentencing part of the hearing, which includes victim impact statements, most likely from Kimberly Vaughn's family.