It was owing to his being near the place when he met his bodily death. Do not direct your mind strongly to the subject, lest he vex you. He has not rested after the violent separation from the body. Well for him if he does so. If not he will remain an earthbound spirit for long.
Rest is a step to progress in the case of such a spirit.
It is to be desired that the poor soul may rest and not haunt the sphere of vice in which his earth life was spent. The mutilation of the body does not harm the spirit, except by the rude shock. And that would stir it into action rather than lull it into repose. It is usual for a spirit so severed from the body to haunt the spot for long after. This power of sympathetic attraction is mysterious to you.