Brian Dugan, right, pleaded guilty to killing 10-year-old Jeanine Nicarico in Naperville, Ill., in February 1983.
"I don't deserve much, probably not anything at all, but I think everyone is entitled to the truth, no matter where it leads," a letter he sent to the Chicago Tribune read.
The media play led him straight to hard time in a lonely cell.
A DuPage County judge has placed Dugan in solitary confinement after learning he violated his orders not to talk publicly about his upcoming sentencing.
On July 28, Dugan submitted a guilty plea in the 1983 murder of 10-year-old Jeanine Nicarico, with the hope a jury will spare his life because he accepted responsibility.
Judge George Bakalis on Tuesday accused the 52-year-old Dugan of "blatantly trying to taint the jury pool" by talking on the telephone Monday to a television producer.
Bakalis also asserted defense attorney Steven Greenberg assisted Dugan in setting up the phone call with an ABC television producer. Dugan's phone calls from the jail are monitored.
Greenberg acknowledged talking to the producer but insisted there were no plans to arrange an interview with Dugan.
Jury selection for Dugan is to begin Sept. 18.