On the night of April 24, 1978, a witness observed a car that was being driven erratically and that eventually swerved off the road, coming to a stop in a field without causing damage to any person or property. Ignoring the witness’ suggestion that he wait for assistance in removing his car, the driver walked away from the scene. The police arrived a few minutes later, and were told by the witness that the driver was either very inebriated or very sick. After checking the car’s registration, the police, without obtaining a warrant, proceeded to the petitioner’s nearby home, arriving at about 9 p.m. They gained entry when petitioner’s stepdaughter answered the door, and found petitioner lying naked in bed. Petitioner was then arrested for driving a motor vehicle while under the influence of an intoxicant in violation of a Wisconsin statute which provided that a first offense was a noncriminal violation subject to a civil forfeiture proceeding for a maximum fine of $200. Petitioner was taken to the police station, where he refused to submit to a breathanalysis test. Pursuant to Wisconsin statutes, which subjected an arrestee who refused to take the test to the risk of a 60-day revocation of driving privileges, petitioner requested a court hearing to determine whether his refusal was reasonable. Under Wisconsin law, a refusal to take a breath test was reasonable if the underlying arrest was not lawful. The trial court, ultimately concluding that petitioner’s arrest was lawful and that his refusal to take the breath test was therefore unreasonable, issued an order suspending petitioner’s license. The Wisconsin Court of Appeals vacated the order, concluding that the warrantless arrest of petitioner in his home violated the Fourth Amendment because the State, although demonstrating probable cause to arrest, had not established the existence of exigent circumstances. The Wisconsin Supreme Court reversed.
Held: The warrantless, nighttime entry of petitioner’s home to arrest him for a civil, nonjailable traffic offense, was prohibited by the special protection afforded the individual in his home by the Fourth Amendment. Pp. 466 U. S. 748-754.
(a) Before government agents may invade the sanctity of the home, the government must demonstrate exigent circumstances that overcome the presumption of unreasonableness that attaches to all warrantless home entries. An important factor to be considered when determining
Page 466 U. S. 741
whether any exigency exists is the gravity of the underlying offense for which the arrest is being made. Moreover, although no exigency is created simply because there is probable cause to believe that a serious crime has been committed, application of the exigent circumstances exception in the context of a home entry should rarely be sanctioned when there is probable cause to believe that only a minor offense has been committed. Pp. 466 U. S. 748-753.
(b) Petitioner’s warrantless arrest in the privacy of his own bedroom for a noncriminal traffic offense cannot be justified on the basis of the “hot pursuit” doctrine, because there was no immediate or continuous pursuit of the petitioner from the scene of a crime, or on the basis of a threat to public safety, because petitioner had already arrived home and had abandoned his car at the scene of the accident. Nor can the arrest be justified as necessary to preserve evidence of petitioner’s blood alcohol level. Even assuming that the underlying facts would support a finding of this exigent circumstance, given the fact that the State had chosen to classify the first offense for driving while intoxicated as a noncriminal, civil forfeiture offense for which no imprisonment was possible, a warrantless home arrest cannot be upheld simply because evidence of the petitioner’s blood alcohol level might have dissipated while the police obtained a warrant. Pp. 466 U. S. 753-754.
108 Wis.2d 319, 321 N.W.2d 245, vacated and remanded.
BRENNAN, J., delivered the opinion of the Court, in which MARSHALL, BLACKMUN, POWELL, STEVENS, and O’CONNOR, JJ., joined. BLACKMUN, J., filed a concurring opinion, post, p. 466 U. S. 755. BURGER, C.J., filed a separate statement, post, p. 466 U. S. 755. WHITE, J., filed a dissenting opinion, in which REHNQUIST, J., joined, post, p. 466 U. S. 756.