During phase 1 of the proceedings Mugford could not possibly have known or suspected that Jeremy had killed his family - she knew about the sighting of a person in the upstairs bedroom window, observed by two police officers and Jeremy, whilst he was outside in the grounds, so obviously in her mind at that stage, how could Jeremy be responsible for killing someone who was still alive upstairs in the bedroom? Mugford also knew the reason why Jeremy complained to PS Saxby that police had shot and killed his family - she knew that Jeremy thought police had shot his family because at the time news was broke to him about his family all being found dead, jeremy had no idea that anyone had been shot at all, and this was reinforced in his mind because of the sighting of a person alive amd moving around inside the house...
If there was / is any truth at all in Mugfords stories which she introduced along the way, it must have been confusing to think that for a year or so, Jeremy had been openly planning to kill his family, and then along comes Sheila who does the job for him - it must have been Sheila because there was someone still alive, moving around in the upstairs bedroom., and besides police said Sheila had done it...