Robin Vander Wall
Double jeopardy will never attach as a reasonable argument against the registries. The prohibition against double jeopardy protects a citizen from being tried twice for the exact same offense or from being punished under more than one statute that contains the same elements or fewer of the same elements already included in the more serious charge (a lesser, but entirely included, offense).
While they are punitive, the statutes requiring registration are not criminal statutes and there is no criminal process involved except for the mere fact of one’s conviction of a sexually based offense. No legislative body has ever explicitly declared that the intent of registry is to punish anyone. Just the opposite, they’ve bent over backwards to make declarations of their civil, non-punitive purpose. And, thus far, no court has ever declared that a state deliberately set out to punish anyone by requiring them to register as a sex offender. And, even were that to happen, it still wouldn’t open the door to a claim of protection from Double Jeopardy (5th Amendment claim) but would throw the door wide open for Fourteenth Amendment Due Process and Eighth Amendment C&U claims.