It was incredibly sick. The poor girl was raped, drugged, and left to die overnight in a cedar trunk in a hot attic in the summer. The next morning, when they found her still alive, they strangled her and then left her in the trunk for months buried in cat litter. When investigators got on the trail, they dismembered the corpse and dumped it in the woods.
Putting a face on this story:
And the rape was from a year-long rape/murder fantasy of the adoptive mother and her boyfriend. And the adoptive mother watched the rape as it happened and was aroused by it.
As sick as it gets in our sick world.