While no official motive was released as to why Jacob killed his mother and brother, Laurie Tonkovic — the wife who swapped with his family — speculated that his lack of free will "caught up to [Jacob.]"
When I switched the rules and I was going to let them have fun, let them have a television and video games, and experience life a little bit, [Jacob] ran outside crying. And when I went out after him, I asked him what was wrong, and he said that his mom and dad would tell him that he would ‘burn in hell.’ God gives you free will – free will, they didn’t have. They weren’t allowed to make choices. I think it just caught up to him.”