Which is why the best option is to execute them when they are convicted.
Absolutely right
The killers of Lee Rigby for instance, when it was beyond any legal doubts they had murdered the poor guy, should have been terminated immediately once convicted.
The best outcome though is what transpired on London Bridge. No doubt about what the bastard had done, so once clearing the members of the public off of him, two lovely shots by the Arms Response Unit dispatched him without any further costs of a trial to reach the obvious conclusion, and the shit being let out again on licence after just a few years! How I loved the sound of those shots and one broadcasted piece of footage that recorded the whole event without pausing before the dispatch
Maybe now things will change so that the public, and police officers, are not put at unnecessary risk, with things going around in legal circles, whilst mamby pamby liberal ideals in the UK's current legal system are followed that allows murders / terrorists who hate our way of life and are out to destroy it, to walk the streets again Terminate them at the earliest possibility.