The Fourth Amendment permits police officers to enter a home when “the exigencies of the situation” create a compelling law enforcement need. The question in Lange v. California was whether pursuit of a fleeing misdemeanor suspect categorically qualified as an exigent circumstance. In this case, the suspect was driving while listening to loud music and honking his horn. When an officer signaled for him to pull over, the suspect instead drove about 100 feet to his home, entering his garage. The officer followed the suspect into the garage and tested him for sobriety, which the suspect failed. The suspect was charged with a DUI. The suspect moved to suppress all the evidence, but California’s state courts denied relief, adopting the categorical rule that a fleeing suspect always creates an exigency under the Fourth Amendment.
The Court, resolving differing views by other courts, held 7-2 in an opinion by Justice Kagan that California’s categorical rule was unconstitutional, and that whether exigent circumstances exist must be weighed on a case-by-case basis, in consideration of all the circumstances to determine whether there is an emergency allowing warrantless entry. Justice Thomas, joined in part by Justice Kavanaugh, filed a concurrence setting forth certain exceptions to the case-by-case rule noted by the majority, such as when a person is arrested and then escapes, and arguing that the exclusionary rule does not apply to evidence discovered in the course of pursuing a fleeing suspect. Chief Justice Roberts, joined by Justice Alito, concurred in the judgment, arguing that hot pursuit alone should qualify as an exigent circumstance under the Fourth Amendment. Justice Kavanaugh filed a concurrence arguing that the difference between the majority’s opinion and the Chief Justice’s opinion is “academic in most cases,” since such situations will almost always involve some kind of exigent circumstance.
A link to the opinion is here: https://www.supremecourt.gov/opinions/20pdf/20-18_cb7d.pdf