rendell's mistress that resulted in him being found of first-degree murder. >> she was my best friendso to hear that was devastating. >> reporter: megan armstrong our close child friends of erika brown. they remember her as a smiling, laughing woman, who was a loving mother. >> she lived her life to the fullest, you know. she lived every day like it was her last. >> reporter: her last days are a mystery, only starting to come to light inside a solano county courtroom. erika's live-in boyfriend, mark randall, was found guilty of murdering her, but her body has yet to be found. for erika's loved ones there is no peace without that final goodbye. so how did prosecutors pull off a conviction without erika's body? they tell cbs it came down to dna linked to mark randall found in a burned-out car. mark and his mistress staging the car to load erika's body, and another vehicle linked to randall found abandoned, with gas containers still inside. >> it's like living a real-like horror film. >> reporter:'s randall's mistress testified she came to his home, and he admitted he hurt erika thinking