>*SPOILER* When the burnt up dude was in the hole in the
>backyard and picked up that piece of fabric, it was part of a
>maid's uniform. That's where Constance buried her after she
>shot her. Now that her grave has been covered over with
>concrete and a gazebo built on top of it, i guess her spirit
>can't escape now.

I'd say the bodies of the dead have to be excavated and removed from the property for the spirits to be free.