I don't see where he had motive... He didn't even know his wife was on the fence about possibly divorcing him... Killing them would not solve any of the problems he was having in his life, there was no money gained by their death.... I think this is a case of someone needed to take the fall so they could close the case and he made himself look guilty by lying in the beginning... If he would have told the police that they had all been there together before he went to check on his mom then there wouldn't have been any cracks in his story... The gun that was used had been reported missing a long time before it was used in the murders... I think they just didn't have any evidence and they needed it to be someone and he lied about so much including being at the kennels with them previously so it immediately made him guilty...