I think it is highly possible DvD was not home in the late evening.
What makes me even more suspicious is that the VD's are so adamant that Danielle was taken AFTER BVD returned home (Interview with John and Ken, KFI Radio). But how could they know if no one had checked on her? If DVD is not the perp, what is the problem with admitting he were not home at the time of the abduction? It can't make them look any worse than they already do.
Correction: he was not home.