But more to your point, Roy Moore has not been arrested. He has not been, and probably will not be, charged with any criminal or civil infraction. He has, however, accepted his party's nomination for a seat in the United States Senate and is currently actively campaigning for same.
It is worth remembering that allegations are not, in and of themselves, proof of wrongdoing. It's also worth remembering that a political campaign is not a trial, that the press does not have the same investigatory powers as the judicial system, and that the "punishment" being threatened is not being able to be a United States Senator after all. It's actually okay for "the court of public opinion" to have a different burden of proof and standard of evidence than an actual court.
"[I]t is better 100 guilty Persons should escape than that one innocent Person should suffer" is a wise and good maxim. "It is better 100 guilty Persons be elevated to high office than one innocent Person should resign from a campaign they had no guarantee of winning in the first place" just doesn't have the same ring to it.