after three weeks, detective cole-hatchard finally persuaded a track phone manager to give him this piece of paper. stephens that? andrea benson. had that name surfaced before? yes, absolutely. all over diana's phone records. josh mankiewicz (voiceover): she was one of those people who had popped into diana's life when diana was in dc. and benson had a rap sheet. so what's going on here? how many people are involved in this? that's the question of the day. josh mankiewicz (voiceover): the other big question, what did diana nadell do while she was in washington, dc? detectives started with her arrival at reagan national airport 9:30 friday morning, the day before peggy was murdered. earl lorence: we got the video from the airport to follow her through the airport and then follow her outside to where she got into a car. josh mankiewicz (voiceover): here's video of diana being picked up curbside. josh mankiewicz: who picks her up? earl lorence: andrea benson. how do you know it's andrea benson? it's her car registered to her. you can read a license plate from those cameras? they're pretty good. josh mankiewic