This is why I say that Jeremy didn't carry out the killings because if he'd have threatened his father with a rifle,Neville would have planted one on him. Less likely to do that if it was a woman. Jeremy would have been no match against his father,rifle or not as I'm sure Neville would have held his own against another man. Jeremy was a squirt against his father
Besides,it wouldn't/didn't enter Jeremy's head to carry out such a massacre. My views,anyway.