where did it go? it was never returned. >> but it was brad's own computer examined by the fbi which coughed up the most accusing evidence of all. evidence he'd already lied under oath. >> the kids fell asleep around 9:00 p.m. i fell asleep soon after. >> brad said he was asleep with his daughters when nancy came home from that party friday night. but brad's computer said otherwise. he was online until about midnight when nancy came home. >> he's been awake on his computer. when she comes in shortly after midnight, we think they argued and that a fight ensues and that's when he strangled her. >> and then the closest thing the prosecution had to a smoking gun, a google map search. prosecutors allege brad typed in the numbers 27518. the zip code for cary. then zoomed into the exact location where nancy's body was found.