[clarification: I'm posting this question here because it is arguably a better forum than scifi.SE]
In "The Reichenbach Fall" (Sherlock season 2, episode 3), Jim Moriarty breaks into the Jewel House at the Tower of London, the vault of the Bank of England, and Pentonville Prison. Of relevance here is the fact that he wants to get caught in the act (e.g., he deliberately stands unmasked in front of security camera, and then waits for the police to find him inside the locked-down Jewel House, sitting on the throne and wearing the Crown Jewels). At his trial, however, the jury unanimously finds him not guilty, and he walks free, much to everybody's surprise. Shortly after, he reveals to Holmes that the jurors declared him not guilty because he had his minions threaten them and their families with death and other horrible consequences, should they find him guilty. The whole chain of events is Moriarty's way of showing Holmes and Watson that he is beyond the reach of ordinary justice.
Question: in UK law, is the judge obliged to accept the jury's not-guilty verdict, even in cases where the defendant is so obviously guilty as in this episode? More precisely, does the judge have the power to ignore the jury's verdict (on the grounds that the verdict is inherently incompatible with the available evidence) and start a retrial with a different jury?
This question, of course, presupposes that the judge either hasn't been threatened or has decided to maintain his/her integrity in the face of threats.
