Anyway,,why murder 5 people when the old grannie was in the throe's of an illness from which there was no recovery ? As it happened,,she sadly passed away the year that Jeremy was jailed anyway.
Jeremy would probably have known,,or had an idea that her days were numbered,,so why go on to kill when he knew that he was her favourite grandchild and would probably do well.
Chances are,,he probably didn't give death a thought.