Mike,,whatever happened,,Jeremy wasn't involved. It's no use saying----------but he said this and he said that,etc,,was arrogant,,contemptible to everyone, was greedy and after all the money.
There has to be HARD proof that he killed everyone,,,and clearly,there isn't.
How do we know if it wasn't either June or Neville that fired that first shot under her jaw ? We don't,do we ? As both would have been tired and weary and at the end of their tethers. If I was to say who did fire that first shot,,I'd say Neville,,accidentally as he tried,,in a struggle,,to retrieve the rifle from Sheila.
It's by no means impossible for Sheila to have self-inflicted that last shot as a suicidal action,,given that women who kill their children,normally comitt suicide themselves.
The time of that first injury happened in the kitchen where both Sheila and Neville were,,so it tallies with what was seen through the window,as two bodies. We don't know how long Sheila would have lain in the kitchen after the first shot,,but because it stated that it wouldn't have killed her instantly,,we believe she got up on hearing the battering ram against the front door,,and vanished up the backstairs of the farmhouse where she shot herself by administering just ONE bullet.