The term “crime against nature” began to be used in statutes in the United States in the 1800s to refer to sexual practices which were deemed “against nature.” The practice of prosecuting certain sexual practices pre-dates the use of the term “crime against nature” and occurred in many nations around the world prior to the 1800s, persisting in some areas today. In the United States, where the phrase was used in criminal law, the concept of a crime against nature was ruled unconstitutional in a 2003 case, although laws using this phrase are still on the books in several states.
A number of different practices were included under the umbrella of this term. Bestiality was deemed a crime against nature, as were oral sex and homosexual activity. In some areas, masturbation was also considered to be a crime against nature. Many of these laws were structured and applied in a way which targeted homosexual couples, especially gay men.
Arguments in defense of retaining such laws pointed out that they could furnish additional charges for certain types of criminal cases. For example, someone being charged with molestation of a child could also be charged with committing a crime against nature. Likewise, people being charged with rape could be charged under crimes against nature statutes as well as statutes pertaining to rape. These laws were also applied in solicitation cases to increase the severity of solicitation charges.
However, some advocates pointed out that these laws were often applied unevenly. For example, if a heterosexual couple were found engaging in sexual activity in public, they would likely be charged with indecent exposure, while a homosexual couple might be charged with crimes against nature in addition to indecent exposure. There were also concerns that such laws could be used to police activities between consenting adults which occur in private, something which many Americans felt uneasy about.
The concept of an act which goes “against nature” has also been challenged by biologists. Study of numerous animal species has shown that all of the activities discussed in the second paragraph do in fact occur in nature, and are quite widespread among some species.
As a consequence of the challenge to the constitutionality of such laws, states with crimes against nature laws on their books do not enforce them. Other areas of the penal code may cover specific issues for which these laws were once used, to ensure that people who commit crimes such as rape and child molestation can be prosecuted to the fullest extent of the law.