Well, as a couple of others have suggested, it *might* be possible to cleanse such a place, but I am personally of the opinion that the circumstances involved (one parent killing another in view of their children) would make it almost impossible to purge, except by fire or something similar. As that would most likely result in the wholesale destruction of the house, I suppose that you might call that a 'final solution'.

I have often wondered if the house we rented in our previous location had some negative energy in it, possibly associated with the circumstances that resulted in two back doors (a messy divorce, from what we were told). I know that family members and others indicated that there was a sense of a past fire in the place, although there was no visible evidence of such.