On Friday, a teenager named Michael Piggin walked free from court when the jury at a second trial failed to reach a verdict. The prosecutors have stated they will not seek a retrial.

You can read more about it in this article which gives further details of the trial and what Michael Piggin was accused of:

...planning to carry out a murderous attack on his former school, a cinema, a mosque and a council office near his home in the Midlands.