The defense argued that the killings were the work of one or more outsiders and that Gustafsson suffered injuries similar to those sustained by the other victims, and therefore would have been incapable of killing three people.
Forsvaret mente modsat at drabene var begået af en eller flere fremmede, og at Gustafsson havde fået den samme form for skader som de andre ofre, og derfor ikke ville have været i stand til at dræbe tre mennesker.