dumb? >> yeah, it does. >> to believe that the police would tell you the truth about something like that? >> he's been playing games for 0 years with us. 30 years with us. you think we're going to shoot straight with you? i don't think so. >> so, naturally, the police lied and told the killer they couldn't trace a disk to him and waited to see if he would fall for it, which he did. rader's last communication was a computer disk filled with more taunts and puzzles. he sent it to a local television station. the police were able to trace it to a dennis and a computer at rader's church. by googling the church name and dennis, the police quickly zeroed in on dennis rader. what nailed him ultimately was the last floppy disk. >> what nailed him was his hubris. he went too far. >> police also used a surveillance tape from that home depot to figure out that the person who dropped off the btk letter was driving a car registered to dennis rader's son.