When police arrest someone without a warrant, the Constitution requires that a judge review the arrest promptly and make an independent probable cause determination before the State can continue holding the person. The Supreme Court set the standard for what “prompt” means in County of Riverside v. McLaughlin, 500 U.S. 44 (1991): absent extraordinary circumstances, a judicial probable cause determination must occur within 48 hours of a warrantless arrest. States may provide shorter windows; Wisconsin operates within that federal ceiling.
The probable cause determination — sometimes called an initial appearance — is not a full bail hearing or trial on the merits. It is the first judicial check on the arrest itself: a court’s independent confirmation that there were valid grounds to take the person into custody. Until that review occurs, the arrested person is being held entirely on the arresting officer’s judgment, with no judicial oversight.
What happens when that 48-hour window is exceeded? Wisconsin courts have been clear that a delayed probable cause determination does not automatically result in dismissal of the charges. Probable cause existing at the time of arrest does not dissipate during the delay. The appropriate remedy for an unreasonable delay is generally suppression of evidence obtained after the point at which the delay became unconstitutional — not dismissal of the case. Courts have held that unless the delay was deliberate and produced actual prejudice to the defendant’s ability to prepare a defense, the charges remain intact even when the State blew past the 48-hour deadline. See State v. Koch, 175 Wis. 2d 684, 499 N.W.2d 152 (1993) (adopting the Riverside rule in Wisconsin and holding that a delayed probable cause determination is not a jurisdictional defect requiring dismissal).
What this means in practice. An unreasonable post-arrest delay is not a windfall for a defendant unless evidence was gathered during that window and that evidence is material to the prosecution. The question a defense attorney asks is: what happened between the arrest and the probable cause determination, and what did the State obtain during that time? Statements the defendant made to police, additional searches, witness interviews — anything produced after the delay became unreasonable is potentially suppressible. That analysis is fact-specific and often significant.
The hours immediately after an arrest are also when the right to counsel matters most. Police may seek statements before charges are filed and before counsel appears. You have the right to remain silent and the right to an attorney — and the time to invoke both is before you say anything, not after. What to do when you are arrested in Wisconsin covers the immediate steps. If charges have been filed, the procedural details of how and when the arrest was processed are among the first things Carson Law Office will examine.
About the author. Christopher S. Carson, J.D., M.A., has practiced law in Milwaukee for 34 years. He holds an M.A. in International Security Studies from Georgetown University, where he was the Bradley Fellow, was formerly with the American Enterprise Institute, and is a contributing editor at the New English Review. Read the full biography.
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Related reading: Arrested in Wisconsin? Your Rights During a Stop, a Search, and Questioning · What to Do If You Are Arrested in Wisconsin: A Step-by-Step Guide · What Is a Deferred Prosecution Agreement in Wisconsin?
This article is general information about Wisconsin law, not legal advice about your situation, and reading it does not create an attorney-client relationship.