I'm sorry guys, but, as much as I hope and pray for Gabriel's safe recovery, I am getting really bad feelings. Especially the longer this drags out, with no sign of him.
That car ride, with Elizabeth and Gabriel driving from Arizona to Texas is a long one. I'm worried he did started crying (as babies do on long car rides with no one to comfort or distract them), and with Elizabeth driving, stressed, tired and a time bomb waiting to go off, she 'lost it', and in a moment of rage, she killed him. Just my gut feelings, and I pray to God I'm wrong.
I think she may not be telling where he is for the same reason that Casey wouldn't tell where Caylee was.