Don't miss The O'Reilly Factor tonight at 8PM.

Tonight ... "The O'Reilly Factor" is on!

A killer comes clean. The man who murdered Jessica Lunsford contacts Bill. It’s the chilling letter that describes how he stalked, kidnapped and brutally killed an innocent child. What he reveals will shock you! Don't miss tonight's exclusive "O’Reilly Factor."

Then, we'll get reaction from Herb Cohen, Mark Lunsford's attorney.

Lawyer: Couey letter ‘smoking gun'