Well, if I remember my Word Origins class from college... Sinister is latin for Left. And, you commonly hear the phrase, "The right hand of God." Which refers to the benign aspect of God. However, this may be too simplistic.Does the gravestone have anything significant to its left, say, another relative?? And, you might want to consider the cardinal direction the left hand is pointing. Cardinal directions have significance in the occult and many religions/mythologies. For example, the East is commonly associated with the path to the otherworld (heaven).