The silencer never left the cupboard.
The idea that either a psychotic SC or psychopathic JB hang around heating up some implement to burn NB's back is absurd. Why would either of them single out NB? Why not June?
He can't burn anyone else's back. The heat would have gone by the time he got upstairs.
Besides which Sheila can't burn her own back in a murder/suicide.
It was a composed and calculated Bamber.
Agree Sheila would not burn Nevill's back.