The evidence is all there in the police file, cops held back from approaching the farmhouse because of Sheila in possession of guns. The 'movement' of a person at the parents bedroom window. It wasn't a 'trick of light' as suggested by Bews , if anything, it was a 'trick of truth'. Added to that was 'movement' of a person' overheard by the operator, a person close to where the phones handset was off its cradle. At the time this occurred nobody outside the farmhouse knew which phone had its handset off the hook, but with the benefit of hindsight we now know that it was in the kitchen. So, by the time the operator checked the telephone line and heard 'this movement' it becomes crystal clear that there was somebody in the kitchen who was ''not dead'.This suggests in the clearest possible terms that at the time the operator made this observation, that either 'dad' or 'the daughter', were 'moving around in the kitchen'. We know that by this time that the anshuzt rifle was 'not resting against the bedroom window' at that stage. So, somebody 'alive inside the farmhouse' must had got control and possession of 'it' at that point. It's no good everybody 'hiding their heads in the sand', like an ostrich, ask yourselves, ' where was the anshuzt rifle at 'all times' prior to someone placing it near the bedroom 'window'? I don't think 'dad' placed it there, I don't think 'mum' placed it there. J 'didn't place it 'there either. Rest assured, that the 'only person' who could have placed that rifle there at that window was 'the daughter'. And, she 'did' place it there in full view, like 'a trophy'. By that stage, the 'others' were 'all dead', but not 'Sheila'...
An 'un-armed' Sheila went downstairs to the kitchen 'contemplating a surrender', but all that changed once the barrel of the cops gun came around the edge of the internal kitchen door...