The Wooden Picket Pen

Thomas and his two boys went on a fairly long trip. The problem with the timeline is that Mary had an unpredictable schedule where sometimes Thomas didn't even know. He said, my boys and I went overnight to pick up some hay and some wood. We came back. The boy found her dead in the cellar. Now I start getting suspicious about Thomas and Mary's relationship. Is there some past history there to cause people to think that Thomas would inflict this level of violence on Mary?