Until the 1980s, most confession evidence was recorded by police and later presented at trial in either a written or an audiotaped format. Electronic recording of interrogations was first mandated in the United States in Alaska in 1985 by the Supreme Court of Alaska in Stephan v. State—based on the state constitution's due process clause. In 2019, 21 states plus the District of Columbia require recording by law in serious cases. Many other cities have voluntarily implemented electronic recording as best practice, including Philadelphia, Boston, San Diego, San Francisco, Denver, Portland, and Austin. Electronic recording of interrogations has become mandatory in approximately 1,000 law enforcement agencies across the country.
