reporter: detectives wondered, did rachel know about the murders before they even happened? and, more disturbing, did she participate? i think she may have been present when julie was killed. i don t think julie would ve gone into the apartment with daniel by himself. reporter: hard even for a homicide detective to imagine. you don t look at a disney princess as a hardened, cold-blooded, callous murderer. reporter: of course, thinking it and proving it were two different things. and perhaps rachel was just another victim of dan s murder plot. there was no physical evidence placing her at the scene of either murder. she and dan both insisted she didn t know about them in advance. two years into the investigation, we made a determination. we didn t have enough to charge her for murder. reporter: instead, on november 20th, 2012, rachel was arrested and charged as an accessory to murder after the fact.
rachel dan was in custody. what s going through my head is shock. this is probably a huge mistake. this gonna be dropped and everything in time for the rehearsal dinner tomorrow night? reporter: detectives didn t fully believe dan s story, so they brought rachel in to see him. she s on the side of the angels when you put her in that room, thinking, she s gonna get daniel to tell me everything? that was our goal. so when was the last time you really saw sam? reporter: dan told rachel the same story he d told detectives. sam killed julie, and then dan helped sam escape. there s nothing he can do at this point to sure, absolutely. make it better? absolutely. he can sure, sure. be truthful with us and truthful with you and truthful with everyone. reporter: then detectives spoke with rachel alone. rachel told them she and dan had received an eviction notice. dan had to borrow money to make the rent. she said dan had told her only recently that he d borrowed the
people dangerous people. so was it her safety that rachel was worried about? detectives didn t think so. she s given herself more time to think about what she s going to tell us when she has to tell us that. and she s protecting dan? she s protecting herself and dan. reporter: they asked her to take a voice stress analyzer, a kind of lie detector. rachel agreed, and the cops hit her with an aggressive question. did you plan the murder with dan? no. reporter: the results came quickly. coming up is the curtain is about to close on rachel? i think she may have been present when julie was killed. i don t think julie would ve gone into the apartment with daniel by himself. when dateline continues. da safe sleep aid. and the 12-hour pain relieving strength of aleve. so.magic mornings happen. there s a better choice. aleve pm.