Summary of County of Riverside v. McLaughlin
Citation: 500 U.S. 44 (1991)

Relevant Facts: Respondent Donald Lee McLaughlin was arrested, without warrant, in Riverside County, California. Following his arrest and during his detention after that arrest, McLaughlin demanded that officials from the County of Riverside justify his arrest and continued confinement through a judicial determination of probable cause. McLaughlin was released, but brought suit claiming that county policies violated his Fourth Amendment rights against seizure without probable cause. While his initial complaint was defective, his essential claim mooted by his release and lacking standing as he failed to demonstrate that the County would likely violate his rights, McLaughlin amended his complaint and added additional plaintiffs similarly situated. McLaughlin alleged that the County of Riverside violated his rights and those of other plaintiffs by failing to provide the probable cause basis for their arrests within a reasonable time, and sought an injunction. The district court agreed, and enjoined Riverside County from further warrantless arrests where they failed make probable cause determinations within a reasonable time. The Ninth Circuit affirmed, upholding a thirty-six hour deadline for future probable cause determinations following arrest.

Issues: Did respondents (plaintiffs) have standing? Do warrantless arrests not promptly followed by probable cause determinations violated a defendant’s Fourth Amendment rights?

Holding: Yes, the parties had Article III standing to maintain this action. Yes, arrests without probable cause must be followed by probable cause determinations within a reasonable amount of time after the arrest.

Reasoning: Justice O’Connor delivered the opinion of the Court. First, she explained the basis for standing. In this case, while the plaintiffs had all been released at the time the suit was commenced, they could still demonstrate injuries fairly traceable to the conduct of the defendant. Although their claims would otherwise been rendered moot through receipt of a probable cause determination, they obtained class certification thereby preserving the merits of their underlying claims. Justice O’Connor explained that claims such as the instant one are inherently transitory, and that the Court is not deprived of jurisdiction merely because the named plaintiffs claims have been rendered moot, rather the exercise of jurisdiction here was a valid application of the relation back doctrine. On the merits of the claim, Justice O’Connor first revisited earlier cases where the Court had already determined that holding individuals arrested without warrant for thirty days without a probable cause determination was unconstitutional. As the majority explained, the policies governing probable cause determinations must balance the important individual rights at stake with the reality of constraints on law enforcement officials properly exercising their duties. While prompt determinations are constitutionally compelled, some flexibility is nevertheless allowed. In balancing these competing concerns, the Court determined that probable cause determinations should be reasonably prompt, but in no case exceed forty-eight hours after arrest absent exigency. The government must demonstrate a legitimate emergency when probable cause determinations occur after forty-eight hours, and defendants can still prove their rights were violated if their probable cause determination was unreasonably delayed but still within forty-eight hours. Finally, while municipalities are free to combine arraignment proceedings or other pretrial matters with probable cause determinations, they must do so promptly or provide legitimate reasons for the delay.

Dissent: Justice Marshall dissented, joined in his opinion by Justices Blackmun and Stevens. In a brief opinion, Justice Marshall explained that the Court had already determined that probable cause determinations must promptly follow arrests, and interpreted promptness to indicate once completion of administrative requirements following arrest had been satisfied, defendants could no longer be held reasonably. Justice Scalia, arguing that the Court set an arbitrary deadline, agreed that the burden should be on the government to demonstrate reasonable cause for delay following arrest, but concluded that a twenty-four hour deadline sufficiently balanced the competing concerns.

Conclusion: The Court, after determining that the parties had standing, balanced competing concerns of defendants arrested without warrant and the realities of law enforcement. In striking that balance, the Court determined that defendants are entitled to probable cause determinations within forty-eight hours of the arrest absent exigency.