Yes and there's no side,there's no cutting off telephone calls for fear of outside intervention(schizophrenics are unaware of law enforcement in a state of psychosis) and they don't kill themselves conveniently for another member of the family who had plotted to kill them for over a year to inherit.
"The trick is to tell the truth wherever possible" was one of Jeremy's most telling statements to Julie as they walked around the block near Julie's parents' house in one of the few times they were alone together after the murders. It portrays an insight into Jeremy's mind as requested by Susan,and explains Jeremy's reluctance to speak to Police after that first morning at Goldhanger,where he did well from his point of view apart from the slip to Julie of the chuckle overheard incredulously by DS Stan Jones and that now infamous comment:"I should have been an actor".
Schizophrenics don't tell the truth,,,as at times they're in denial anyway,,so could be talking to you and I quite lucidly one minute,,,then the next second,,pull a knife from nowhere.
They see things that aren't there,,,or are not as others see.
They also hear voices telling them to kill.
Sheila had obviously reached a point of no return as there was only so much medication that could be had for her type of psychosis.
Sheila,,if anyone,was the actress,,,as one minute,,,silent and deep in thought,,then the next,rifle in hand and whizzing around the place like a Dirvish.
When Dr Ferguson gave evidence,,he had the temerity to state that which Sheila had told him about killing the children and committing suicide,,,but sadly,,,or carelessly,,he took no heed to the warning signs and stated more or less that neither her nor her children were in danger.? I'd have questioned that for starters,,,as either contradictory or that he wasn't fully conversant with the illness.