Mugford wasn't charged with being an accessory because the police know what she had to say had no truth to it, she was just there to fill in the gaps to try and get Jeremy arrested and convicted in connection with the deaths. She would have said anything, and she did, it was irrelevant whether what she said at one time or another was proven or disproved, police would not prosecute her because she was worth more to the prosecutions case, than any desire to prosecute her for being a criminal type...