She never changed her story, she added to it and most effectively if I may say so.
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Sorry, she did not add to it, she changed her story as the time progressed, first it was a hitman killed the family, and that JB paid him 2000 pounds, then it turned into JB doing it himself - now if that isn't changing her story, I don't know what to say?
According to her in her original statements, a hitman did it, but no sooner does McDonald get cleared by a reliance upon an alibi, Mugford changes her story, and makes out JB was the person who actually carried out the murders, now if that isn't changing her story, then you need urgently to educate me...
I don't believe that's true Mike? She didn't change her story. Mcdonald was even in court. Surely she wouldn't have even thought of the Mcdonald story if she hadn't been told it by JB. If she'd wanted to 'frame' JB she would have just done it from the outset. She lied to the family though, seemingly to cover for JB, especially when she identified the bodies.
... Well, I look at this matter from a different perspective - since, Mugford knew more than you or I give her credit for? By the time she was coerced to come forward, she was already in possession of information, which depending upon which way you choose to look at it, either proved Jeremy could not have been responsible for killing his entire family and then stage managing Shiela's body in the bedroom to make it appear as though she had taken her own life, or that because there had been a sighting of a person at the bedroom window, a sighting which had been witnessed by Jeremy, PC Myall and PS Bews, there must have been an accomplice, or as the case may be, somebody who was hired by Jeremy to kill his family - the only other alternative, was that Shiela really did kill the others, and then herself. These were the options available to Mugford at the time she decided to put Jeremy in the frame. Mtgford was a wounded animal at the time she was plotting jeremy's downfall, and with the cunning nature, akin to a vixen, she knew what to say, and how to say it - she didn't need to get any information about McDONALD, from Jeremy at all, it was commonly known in Jeremy's circle of friends and associates, that Mathew McDONALD had a bit of a reputation of being a mercenary (hitman), and somebody with the guile that Mugford possessed, would readily be able to piece together a story to fit the occasion, and this is precisely what she has done...