that's why we didn't arrest him right away. >> police needed to see exactly what k.c. joy was doing on those library computers. that would require a very unusual plan. they obtained a search warrant allowing them to watch in realtime every move made on the computer. this is a recording of k.c.'s actual computer keystrokes and mouse clicks. that's k.c. checking his e-mail. that's k.c. applying for a job. that's k.c. typing in how long does it take a body to decay. suspicious maybe, but not enough. and then he did this. >> he pulled up a facebook page that showed there was going to be an awareness walk in the near future. >> a walk to help find maribel? >> it was. he google mapped that park and zoomed in onto it. he then panned out, navigated