Right around the time Katie McCarron was killed, so was Christopher DeGroot

[conuly]

It's hard to tell from the comments to this article, but his parents almost certainly set the house on fire. That was the conclusion the police made in the first articles on the subject, and nothing has actually changed as far as I'm aware. They just managed to not be tried for arson, only for locking their kid in his room while they left the house for several hours.

That might help to explain why they were each convicted to only six months in prison.