He believed that A... they wouldn't find the bodies, and or B. he could never get convicted.
Hubris and a murdering SOB, not a good combo.
Right. And you can add STUPIDITY to the list. If he hadn't admitted going to the marina that day, the bodies would never have been found. I hope the police hang life-sized full-color glossies of the decomposed bodies of Laci and the baby on the walls of Scott's cell.