I don't believe the abductor took the phones intentionally, but rather Jennifer had them both on her when she was abducted and the abductor found out later. Of course, when would she likely have both phones and it would seem that would be when she was leaving the apartment that morning. Another argument for a morning abduction. (However, I could see an argument that Jennifer had his phone in her briefcase and she put the briefcase in her car the night before.) I'm leaning toward a morning abduction, but I'm keeping an open mind about one that night.
We've heard her briefcase and possibly her purse were never found. I can imagine that whoever did this hid a body first and then went about disposing the briefcase and purse and it was then they may discovered the phones. This is 2006 and I only just purchased my 2nd cell phone a year before and that 2nd phone had texting capability. I'm trying to think back and remember hearing about phone pings and their importance in LE investigations in 2006. I'm sure we did, but I'm thinking it wasn't as widely known as it is now. Would a laborer, especially one who might be an illegal alien, know about such technology in 2006? The elimination of the phones by turning them both off would lead me to believe this wasn't likely one of the workers.
I still find the fact that Jennifer had two phones on her and this doesn't help LE. I'm sure it is entirely possible that both phones pinged on the same cell tower. But didn't LE or Drew Kesse state something to the effect that Jennifer couldn't be in two places at the same time? Were the phones pinging off two cell towers? If that were so, wouldn't that make it easier to triangulate the position where both were turned off?