In what manner are you speaking about, with the prosecution and how they treat the alleged criminal?Please. Of course a reasonable prosecutor ought to believe that the person he or she has accused is guilty.
But they are still required to treat them as though they aren’t. It’s not even a question. They are obligated by their oaths to do so.
How would the prosecution's treatment differ between a presumption of innocence vs a presumption of guilt?
Basically, I have no idea what you are talking about? The moment the grand jury or prosecution indicts...they indict with the presumption of them being guilty and then it goes to trial....and the prosecution takes the stance of proving their guilt in a court of law....beyond a reasonable doubt.
If they fail to do so, then they accept the jury's decision of not guilt...