. >> reporter: back in 1994, katherine fernandez-rundel had been the miami-dade state attorney for two when the case came into her office. she was determined lynne friend's name would not end up in some cold case file. >> this was not the easiest case, as you might imagine. >> reporter: couldn't say if she was dead. she might have metaphorically taken the midnight train to georgia. nobody knew. >> that's correct. we didn't know she was missing. we believed it. we had a little boy. we didn't know what he was going to say. we didn't have access to him. really what you had was very little. so you had to really build it, you had to stay tenacious. >> reporter: tenacious indeed. because clifford friend actually had an alibi. [ sirens ] >> reporter: one he wasn't proud of, perhaps, but it explained what he was doing that night and why there were two men in a boat. >>> coming up, an undercover sting that didn't quite go as planned. >> he said, "oh, i took the recording device and dropped it in her diaper." "let life in with new herbal essences bursting with argan oil of morocco and notes of j