Justice Kagan continued in relevant part: Under the Fourth Amendment, pursuit of a fleeing misdemeanor suspect does not always—that is, categorically—justify a warrantless entry into a home. The Court’s Fourth Amendment precedents counsel in favor of a case-by-case assessment of exigency when deciding whether a suspected misdemeanant’s flight justifies a warrantless home entry. The Fourth Amendment ordinarily requires that a law enforcement officer obtain a judicial warrant before entering a home without permission. Riley v. California, 573 U. S. 373, 382. But an officer may make a warrantless entry when “the exigencies of the situation,” considered in a case-specific way, create “a compelling need for official action and no time to secure a warrant.” Kentucky v. King, 563 U. S. 452, 460; Missouri v. McNeely, 569 U. S. 141, 149. The Court has found that such exigencies may exist when an officer must act to prevent imminent injury, the destruction of evidence, or a suspect’s escape.
The amicus contends that a suspect’s flight always supplies the exigency needed to justify a warrantless home entry and that the Court endorsed such a categorical approach in United States v. Santana, 427 U. S. 38. The Court disagrees. In upholding a warrantless entry made during a “hot pursuit” of a felony suspect, the Court stated that Santana’s “act of retreating into her house” could “not defeat an arrest” that had “been set in motion in a public place.” Id., at 42–43. Even assuming that Santana treated fleeing-felon cases categorically, that statement still does not establish a flat rule permitting warrantless home entry whenever a police officer pursues a fleeing misdemeanant.
It is unlikely that the state patrol officer in this case was even aware of the federal misdemeanor of “failing to comply with a police signal.” That offense is classified as an obscure motor vehicle offense in New Jersey under N.J.S.A. 39:4-15.