The US Supreme Court [official website] on Monday ruled [opinion, PDF] 5-4 in City of Los Angeles v. Patel [opinion, PDF] that police must obtain a search warrant before demanding to inspect a hotel’s guest list. At issue was a Los Angeles law [Los Angeles Municipal Code § 41.49, PDF] requiring hotels to keep specific records on guests and make them immediately available to police on request, or else face criminal charges. The city had argued that the law could not be challenged facially – based on its text alone, without a specific example of its application. Writing for the court, Justice Sonia Sotomayor disagreed, saying the bare text of the law alone violated Fourth Amendment rights against unreasonable search and seizure [LII backgrounder], because it gave hotel operators no chance to challenge the search before complying with it. Sotomayor went on to say that the city could continue to require the records to be kept and that existing doctrines already protected law enforcement’s interests:

nothing in our decision today precludes an officer from conducting a surprise inspection by obtaining an ex parte warrant or, where an officer reasonably suspects the registry would be altered, from guarding the registry pending a hearing on a motion to quash.

The ruling upheld an earlier decision [opinion, PDF] by the US Court of Appeals for the 9th Circuit [official website].

Justice Antonin Scalia filed a dissent, joined by Chief Justice John Roberts and Justice Clarence Thomas. Justice Samuel Alito also filed a dissent, joined by Justice Clarence Thomas. The court granted certiorari [JURIST report] to the case in October and heard oral arguments in March.