Yes let's
There is no evidence
Jeremy admitted prior to the murders to replacing the kitchen phone with the bedroom phone. He claimed it was because the kitchen phone was broken but in fact the kitchen phone worked fine he just hid it so noone would realize it wasn't broken like he claimed.
There is no evidence that Sheila killed loaded a gun let anyone else but if she actually had been the killer then such evidence would exist. There would have been clothing with medium velocity spatter from Nevill and high velocity spatter from the victims. There would have been GSR on her clothing as well. She also would have had injuries from walking in the glass of the broken lampshade, crockery and on her hand from the broken rifle stock. The claim she would have washed before killing herself is ridiculous but injuries can't be washed away nor can clothing simply vanish. If she changed the clothing with the spatter and GSR would have been there. She still would have gotten GSR on the gown she died in and her hands if she fired the fatal shots. Had she hugged the wepaon to shoot herself the GSR woudl have been on her gown. None was found because Jeremy held the gun away from her with the moderator attached and thus the area of the gun where GSR is expelled wa sno where near her body for those 2 shots.
There is no evidence Sheila knew how to use a gun of any kind let alone a semi-auto rifle (until November 30, 1984 they never had any semi-autos so growining up on the farm had not exposed her to any)
There is no evidence that Nevill could have made a call to Jeremy based on how the murders went down. If he had been caught on the phone by Sheila then she would have shot him in the kitchen. The shooting started in the master bedroom with both parents present and being shot. In the meantime he would have tried to disarm her himself not to call his weaker son to come do it. Worse still his son had an asnwering machien and the phone was on a different level than his bedroom so even if he heard the phone the answering machine would have picket up before he could reach it. Nevill would have to have left a message but had not. Nor would Sheila have bothered to leave the phone in the kitchen off the hook so no one coudl use it, that is something Jeremy would do- the guy who made sure no phone was in the master bedroom.
There is no evidence that Nevill ever removed the scope and moderator from the weapon when storing it let alone used it without them. In fact there is no evidence Nevill used the murder weapon more than a couple of times. There is no reason to remove the scope other than close quarter shooting like the murders. Jeremy at one point admitted to removing the scope himself but when he became a suspect changed it to Neivll removing it. He admitted he had not touched the rifle the week prior to the murders but after the last known user said it was put away with the moderator and scope attached he changed his story and made up the obvious lie that Nevill and himself had used it repeatedly over the course of the week prior to the murders and that during this period the scope and moderator were removed and reattached numerous times and the gun sometime was used without them.
There is no evidence that Jeremy ever shot rabbits, instead there is evidence that he was opposed to shooting them making his claim he took out the gun to shoot rabbits even more suspect than just suspect because of the time of day and absurdity of his claims that he would use it without the scope or moderator to shoot rabbits.
There is no evidence that the killer would use 20 bullets from the supply Jeremy left in the kitchen but to go get 5 addiitonal rounds from the closet though 30 remained in the kitchen. QUite obviously those bullets were staged by Jeremy after the murders. Neither during his interviews nor at trial coudl jeremy even think of a lie to account for this problem.
There is evidence that the moderator was used during the murders. DUring the scuffle with Nevill the moderator broke the ceiling lampshade, scratched underneath the mante in a zigzag patterns and knocked things onto the floor. The gun would have been too short to break the ceiling lampshade without the moderator attached. Someone just dropping the gun or walking by and scratching the mantle would have left a lateral scratch. The scratches on the mantle indicate a struggle over control of the weapon was taking place. It was still attached when Sheila was shot because the fatal shot was a contact shot and resulted in drawback into the moderator, had the moderator not been attached instead the muzzle of the weapon would have had blood in it.
In a crazy rage Sheila would not have gone to the closet to get the moderator to attach to the gun let alone would she be able to remove it and put it away after killing herself. Nor after she was dead could she have moved her body flat and then opened and closed the bible in a pool of blood that formed after her death. Someone else had to be there doing these things and that person would be the killer.
There is no evidence that Jeremy acted in any way shape or form like someone would act if they actually received a call that he claimed to received. Instead of rushing there to help or calling police then rushing there he called Julie and woke her up just so he could use her to support his alibi. His plan was to tell police he called her to demonstrate his concern and this proves he really did receive a call. He had no valid reason to wake her up that is why he did it. He called her again at 6AM telling her not to go to work because she would need to talk to police and tell them about his call to her. This was 1.5 hours before they found any bodies. In the meantime police had to tell him to go meet them there. He drove there as slow as he could to avoid beating police there. As police approached the last mile they observed a car driving very slowly as as they caught up to it the car pulled over on the side of the road. this was only a mile form WHF. That car was being driven by Jeremy. He waited on the side of the road for 3 minutes he didn't simply get out of the way for police to pass. After waiting on the side of the road for 3 minutes he finally drove the last mile to WHF. Police recognized his car and asked what took him so long to drive a mile and he was doing on the side of the road. He gave the excuse that he got cold and stopped to put on a sweater. He wanted to make sure they could say they beat him there to back up his alibi that he had been home leeping when he received a call from Nevill.
Upon meeting them he told them his sister was a nutter and the whopper of a lie that there was an arsenal of weapons is the house and that his sister was proficient with all of them expecially a rifle he had left on the kitchen table. He made no effort to go investigate himself and scare dthem so tha they woudl not do so either instead they requested armed support. He calm sat around tlakign to them about cars and guy stuff.
Nothing he did comported with someone who left a rifle out and such rifle was used to commit murder.
Last there was Julie's very detailed and specific testimony of how long he had been planning to kill his family, the phone call to her around 10PM the night of the murders where he said tonight is the night and his admisisons that he was responsible after the murders.
This is all proof Jeremy did it.
There of course is more but this is the main evidence.
There is no evidence at all to support that Sheila did anything but plenty to convict Jeremy.