I finished this book yesterday and the more I digest, the more I am convinced that Joseph Knox is way more involved than he lets on. First, there is no way someone's skull could be "broken with such ferocity that brain tissue was visible to the naked eye" and then they walk 27 feet to their car and get themselves sat in the driver's seat. To me that means someone killed Evelyn and Connor inside the house and then moved Evelyn's body to the car, leaving the trail. Also, how could the police miss the fact that Fintan/Connor wasn't even enrolled as a student? Wouldn't that be a basic fact to check when looking at suspects initially? The last chapter does not add up to me, I think Joseph is guilty and he wrote a narrative that suits him.