I've been following this horrible and mysterious story since it happened. I feel terrible for everyone involved in both families. I've been trying to come up with an explanation as far as a motive for this senseless act and I thought of a couple of possibilities:
1. Sherwin's parents leave for their early morning walk, and Sherwin decides to take a look at the family gun. He's playing around with it and it accidentally discharges. He runs outside and sees that the bullet has gone into the neighboring tent, killing Sara and Lula Schmidt with one shot. Tyler Schmidt sees Sherwin come in the tent holding the gun, and he attacks him in self-defense and in retribution for killing his wife and daughter. Sherwin then shoots Tyler. (Only two shots were fired according to witnesses). When Sherwin sees what he's done, he is overcome with fear and runs into the woods, where he shoots himself rather than face the consequences.
2. Sherwin had his eye on either Sara or Lula Schmidt and intended to abduct and molest/rape them at gunpoint while his parents were on their early morning walk, but he met with resistance and he opened fire, then ran off and shot himself in guilt and fear. Perhaps he planned to wake one of the females and lead her into the woods silently at gunpoint?