The U.S. Supreme Court ruled on Monday that a Los Angeles city ordinance that lets police view hotel guest registries violates the privacy rights of business owners.
In a 5-4 decision, the court upheld an appeals court ruling that struck down the ordinance that was intended to deter crimes including prostitution.
The city appealed after the San Francisco-based 9th U.S. Circuit Court of Appeals struck down the ordinance in December 2013.
The city called the law crucial to efforts to reduce criminal activity especially in so-called parking meter motels that charge by the hour and are often used for prostitution and other crimes.
Hotel operators challenged the law, saying it violated their privacy rights under the U.S. Constitution's Fourth Amendment, which protects against unlawful searches and seizures.
The ordinance requires hotel and motel operators to collect a detailed list of information on each guest, including name and address, car model, license plate number and method of payment.
The records are available for inspection by the police department at any time, without a warrant.
Lawyers for the city said its ordnance, and dozens of others like it around the United States, are vital tools for law enforcement when investigating such issues as prostitution, gambling and even suspected militant activity.
The case is City of Los Angeles v. Patel, U.S. Supreme Court, No. 13-1175.