josh mankiewicz (voiceover): what mr.er officers were watching him 24/7. the surveillance teams noticed he was spending a lot of time at the public library, and he was using the computers there, probably because police had taken away his phone and maribel's computer, which was the one kc normally used. joey ramirez: initially, we would have undercover policemen go into the library, walk around him, see what he's doing. and at one point, he's seen googling "can a cell phone be tracked if it's turned off." well, that's certainly suspicious. it is. josh mankiewicz (voiceover): detective ramirez was consulting daily with orange county deputy district attorney scott simmons. there are things that can be called into question, but they're not immediately proof of anything. exactly, and that's why we didn't arrest him right away. josh mankiewicz (voiceover): police needed to see exactly what kc joy was doing on those library computers. that would require a very unusual plan. they obtained a search warrant allowing them to watch i