The test in the criminal law is "the jury must be sure of guilt".
It's actually the prosecution must prove guilty beyond all doubt.
Even if there's 0.01% doubt then the accused must be acquitted.
Half right, and wrong. The criminal test is that guilt must be proven beyond reasonable doubt. What ‘reasonable’ means is deliberately not quantified; all we can say for sure is that it is stricter than ‘the balance of probabilities’ and less strict than ‘absolute certainty’. However I would observe that the criminal standard of proof is generally considered to be a very high one, tending towards the ‘certain’ end of the spectrum. ‘The jury must be sure’ is a formulation which guides laymen towards that without requiring 100% mathematical certainty.