Welsh v. Wisconsin, 466 U.S. 740 (1984), was a 1983 case before the US Supreme Court determining that a warrantless home arrest without exigent circumstances violates the Fourth Amendment protection against unlawful search and seizure.

[9] The increasing number of fatalities caused by drunken drivers has aroused state legislatures to adopt stricter penalties in the forms of substantial fines, imprisonment, and license suspensions to punish those who violate the laws prohibiting driving while under the influence of an intoxicant.[10]."

Presumably, this four-hour statutory limitation sought to provide an adequate time allowance for the arrested intoxicant's blood alcohol content to metabolize to a safer level, equal to or less than .05 percent.

Without an immediate blood alcohol test, highly reliable and persuasive evidence facilitating the state's proof of the defendant's alleged violation of sec.

Justice William Brennan authored the majority opinion, stating that," Page 466 U. S. 749 that the Court has recognized, as "a 'basic principle of Fourth Amendment law[,]' that searches and seizures inside a home without a warrant are presumptively unreasonable."

Consistently with these long-recognized principles, the Court decided in Payton v. New York, supra, that warrantless felony arrests in the home are prohibited by the Fourth Amendment, absent probable cause and exigent circumstances.

Whether there is reasonable necessity for a search without waiting to obtain a warrant certainly depends somewhat upon the gravity of the offense thought to be in progress as well as the hazards of the method of attempting to reach it.

It is to me a shocking proposition that private homes, even quarters in a tenement, may be indiscriminately invaded at the discretion of any suspicious police officer engaged in following up offenses that involve no violence or threats of it.

In a leading federal case defining exigent circumstances, for example, the en banc United States Court of Appeals for the District of Columbia Circuit recognized that the gravity of the underlying offense was a principal factor Page 466 U. S. 752 to be weighed.

We therefore conclude that the common-sense approach utilized by most lower courts is required by the Fourth Amendment prohibition on "unreasonable searches and seizures," and hold that an important factor to be considered when determining whether any exigency exists is the gravity of the underlying offense for which the arrest is being made.

The State attempts to justify the arrest by relying on the hot-pursuit doctrine, on the threat to public safety, and on the need to preserve evidence of the petitioner's blood alcohol level.

Page 466 U. S. 754 Even assuming, however, that the underlying facts would support a finding of this exigent circumstance, mere similarity to other cases involving the imminent destruction of evidence is not sufficient.

Given this expression of the State's interest, 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.

And it is amazing to me that one of our great States—one which, by its highway signs, proclaims to be diligent and emphatic in its prosecution of the drunken driver—still classifies driving while intoxicated as a civil violation that allows only a money forfeiture of not more than $300 so long as it is a first offense.

Justice Byron White filed a dissenting opinion, which was joined by Justice William Rehnquist, arguing that the State of Wisconsin's interest to combat drunk driving, along with Welsh's behavior, was in line with the Fourth Amendment, Welsh did not use the exclusionary rule when it came to the breathalyzer test, A test relying on exigent circumstances to weigh the gravity of the crime would hamper law enforcement, the Court ignores the benefits of the statute and solely relied on the penalties of the first offense, and that common law justified the arrest ," "a peace officer was permitted to arrest without a warrant for a misdemeanor or felony committed in his presence as well as for a felony not committed in his presence if there was reasonable ground for making the arrest."

In the civil license revocation proceeding, Welsh argued that his arrest in his house without a warrant was unconstitutional under the Fourth and Fourteenth Amendments to the Federal Constitution, and that his refusal to submit to the test could not be used against him.

The court acknowledged that "the individual's right to privacy in the home is a fundamental freedom," and made clear that the State bore the burden of establishing exigent circumstances justifying a warrantless in-home arrest.

In providing that a driver may reasonably refuse to submit to a sobriety test if he was unlawfully arrested, Wisconsin's Legislature and courts are pursuing a course that they apparently hope will reduce police illegality and safeguard their citizens' rights.

Page 466 U. S. 760 As a practical matter, I suspect, the Court's holding is likely to have a greater impact in cases where the officer acted without a warrant to prevent the imminent destruction or removal of evidence.

If the evidence the destruction or removal of which is threatened documents only the suspect's participation in a "minor" crime, the Court apparently would preclude a finding that exigent circumstances justified the warrantless arrest.

Wisconsin's Legislature and its Supreme Court have both concluded that warrantless in-home arrests under circumstances like those present here promote valid and substantial state interests.

The Court relies heavily on Justice Jackson's Page 466 U. S. 761 concurring opinion in McDonald v. United States, supra, which, in minimizing the gravity of the felony at issue there, illustrates that the need for an evaluation of the seriousness of particular crimes could not be confined to offenses defined by statute as misdemeanors.

There may have been a time when the line between misdemeanors and felonies marked off those offenses involving a sufficiently serious threat to society to justify warrantless in-home arrests under exigent circumstances.

If I am correct in asserting that a bright-line distinction between felonies and misdemeanors is untenable and that the need to prevent the imminent destruction or removal of evidence of some nonfelony crimes can constitute an exigency justifying warrantless in-home arrests under certain circumstances, the Court's approach will necessitate a case-by-case evaluation of the seriousness of Page 466 U. S. 762 particular crimes, a difficult task for which officers and courts are poorly equipped.

As the Court observes, the statutory scheme in force at the time of Welsh's arrest provided that the first offense for driving under the influence of alcohol involved no potential incarceration.

Nevertheless, this Court has long recognized the compelling state interest in highway safety, South Dakota v. Neville, 459 U. S. 553, 459 U. S. 558-559 (1983), the Supreme Court of Wisconsin identified a number of factors suggesting a substantial and growing governmental interest in apprehending and convicting intoxicated drivers and in deterring alcohol-related offenses, 108 Wis.2d at 334–335, 321 N.W.2d at 253–254, and recent actions of the Wisconsin Legislature evince its "belief that significant benefits, in the reduction of the costs attributable to drunk driving, may be achieved by the increased apprehension and conviction of even first time .

The Court ignores these factors, and looks solely to the penalties imposed on first offenders in determining whether the State's interest is sufficient to justify warrantless in-home arrests under exigent circumstances.

It is possible, moreover, that the legislature consciously chose to limit the penalties imposed on first offenders in order to increase the ease of conviction and the overall deterrent effect of the enforcement effort.

As the Supreme Court of Wisconsin observed, "[t]his is a model case demonstrating the urgency involved in arresting the suspect in order to preserve evidence of the statutory violation."

In light of the promptness with which the officers reached Welsh's house, therefore, I would hold that the need to prevent the imminent and ongoing destruction of evidence of a serious Page 466 U. S. 764 violation of Wisconsin's traffic laws provided an exigent circumstance justifying the warrantless in-home arrest.