Adultery still a felony in Idaho

The crime is rarely prosecuted, but it remains on the books as a relic of America’s long history of regulating sexual activity.

Historically, adultery has been criminalized as a way to control the public’s behavior, said Elizabeth Brandt, a University of Idaho law professor.

Much like the era of Prohibition at the turn of the century, the strict laws were seen as a way to reduce threats to marriage. Today, that fear has waned despite adultery remaining a crime, Brandt said.