These are edited parts of the recap from episode two from TWoP (thank you) which leads me to believe that there was a murdered child, and Paul was trying to destroy the evidence. I also added a few items that I remember from the episode.
Help me out here if you remember something else.
Over at the Mary Alice home, where the pool has been totally dug up, Paul drags what looks like a child's toy chest into his shed and looks shiftily at it.
Paul loads the toy chest into the back of his SUV and then slams the trunk. Paul gets in the car and drives off.
At night, Paul takes the chest out of the back of the car and throws it in a lake or body of water.
Later, Paul sees a news report on TV about the toy chest that surfaced in the water. The news reporter announced that the chest contained bones of a small body. Zack walks in and Paul shuts off the TV quickly so he doesn't see the news report.
Make of it what you will. It was only the second episode. The information is interesting, yet confusing, considering all the new information we have learned.