According to the limited reports the signs point to him just having a serious fall, then the wife possibly being grief stricken and overdosing on a couple of different medications, but the suspicious factors are one of the dogs being locked in a room (the other two were not) and the front door being unlocked and left partially open.
People are on there phone all the time, so once they get a few phone records they should be able to get a pretty accurate time estimate of how things played out, that and the toxicology reports I think are likely going to explain things.
