Long after criminal laws have lost their vigor in the context for which they were drafted, they may rise again elsewhere. The American legal system has yet to develop a coherent policy delineating when or if historically unenforced penal statutes can be invoked in non-penal contexts. This issue is particularly evident in cases where the relevant laws are caught between shifting moral sentiments. Fornication, for example, remains illegal in many states, but it is rarely prosecuted. Should one of the participants in this "criminal" act contract a sexually transmitted disease and sue her partner in tort, however, these disused statutes may be invoked under the "clean hands" doctrine to bar recovery. There is a growing body of ill-considered, contradictory case law regarding the legitimacy of such non-criminal invocation of profoundly disused criminal laws.
Undead Laws: The Use of Historically Unenforced Criminal Statutes in Non-Criminal Litigation,
Yale L. & Pol'y Rev.
Available at: https://digitalcommons.law.yale.edu/ylpr/vol16/iss1/5