This is just a thought on what could have happened that day/night.
Since RE's father was so sure that IF RE hurt Lonzie it wouldn't have been intentional, would it be out of the realm of possibility that it may have been an accident? He (RE) said something to the effect of he didn't want LLB to go to work (because of the condition of the baby?) and she went anyway cause they needed the money (heartless, distancing herself?). The picture in the over sized cowboy boots is taken next to what appears to be a staircase. Could he have fallen down those stairs earlier in the day in the boots and received his injuries due to no one paying attention? Taking pictures later in the day/night and after LLB went to work to show the condition that SHE left the baby with him instead of getting the baby care, so he would not be blamed for it by DCF (self preservation) if it came up due to the visitor noticing the injuries? Then Lonzie passed on HIS watch, and he came up with the abduction plan to distance himself (self preservation again?) from the baby. I sure wish there were a time stamp to see just when the pictures were taken, and I'm sure JSO has it. Seems to me he didn't want JSO to have the pictures though...He LET them search the car and THEY WERE ABLE to check my phone (as opposed to LET them).
Ebron: No, they wanted to search the car so I let them. They were able to check my phone on the spot. I told them there were no passwords, no locks. The picture for the Amber Alert was off my phone.
http://jacksonville.com/breaking-news/2015-07-31/story/florida-star-interview-william-ruben-ebron
I also had the theory Lonzie could of fallen down those stairs when he should of been properly watched. Maybe RE & LL were high on drugs and forgot about Lonzie? But then i think about LE stating they are treating it as a murder investigation, which to me says they think Lonzie has died and they are building a case for murder against RE & maybe LL too with what they know now?