If the neighbors had heard or seen a ruckus, and called 911, and the police came and found 2 dead girls, and 2 parents, pummeling each other. it would have been a 'he said/she said' battle.
And if that had happened, and they both pointed fingers at the other, then I would be 50/50 on which one was the killer. I know that both mothers and fathers kill their kids, tragically enough.
So I would be open to looking at the videos and the SM posts and hearing from friends/family, to try and figure out which one did this horrible deed.
But in this case, he is pointing his finger at a pregnant dead woman, who was likely killed in the same way as his daughters were. And his explanation of events just seems very sketchy and unreal. JMO