undercover detectives diane harris and sheryl comstock would use to capture a crucial interview with arturo gutierrezsuspect in the murder of christie fleming. in the southern california desert town of perris, the two detectives rolled up to gutierrez's house unannounced. their excuse? they tell him they were conducting a few perfunctory interviews before filing away the old case for good. their plan, to charm him into talking, catch him in a crucial lie, get it on tape. >> instead of fear, i would just say that what i was feeling was excitement, and i was a little on edge. but you have to kind of keep all that down so that it doesn't show through the facade you're putting on. >> the surveillance van was nearby for backup, the tiny tape machine rolled. >> i'm detective comstock, this is detective harris from the sheriff's department. >> how you doing? >> nice to meet you. >> and you like art or arturo? >> it doesn't matter. >> he seemed like a really nice guy. if you were to just meet him on the street, you wouldn't think, my, god, this guy's a murderer. >> it started with an idle and innocuous conve