The presumption of innocence is a legal principle that every person accused of any crime is considered innocent until proven guilty.
Under the presumption of innocence, the legal burden of proof is thus on the prosecution, which must present compelling evidence to the trier of fact (a judge or a jury). If the prosecution does not prove the charges true, then the person is acquitted of the charges.
> The presumption of innocence is a legal principle that every person accused of any crime is considered innocent until proven guilty.
That should be "considered innocent by the legal system". People are still free to come to their own conclusions--and act on them--even without a jury rendering a verdict.
Rather famously, for example, OJ Simpson was acquitted by a jury of murdering his wife. But most people these days would agree with the statement that he murdered his wife.
It is also the case that prosecutors need to decide both the probability of conviction, the effort needed to do so and whether likely conviction on other serious charges are sufficient for the people to feel that justice has been done.
Under the presumption of innocence, the legal burden of proof is thus on the prosecution, which must present compelling evidence to the trier of fact (a judge or a jury). If the prosecution does not prove the charges true, then the person is acquitted of the charges.