Law, College of


Date of this Version

Spring 2-12-2020


Ryan P. Sullivan, Revitalizing Fourth Amendment Protections: A True Totality of the Circumstances Test in § 1983 Probable Cause Determinations, 105 Iowa L. Rev. 687 (2020).


The Article analyzes claims of police misconduct and false arrest, specifically addressing the issue of whether a police officer may ignore evidence of an affirmative defense, such as self-defense, when determining probable cause for an arrest. The inquiry most often arises in § 1983 civil claims for false arrest where the officer was aware of some evidence a crime had been committed, but was also aware of facts indicating the suspect had an affirmative defense to the crime observed. In extreme cases, the affirmative defense at issue is actually self-defense in response to the officer’s own unlawful conduct. As police brutality and false arrest claims rise, so too will the prevalence of this issue.

The Article brings some analytical coherence to the complicated legal and factual situations that may lead courts to abandon certain traditional rules governing probable cause in favor of more leniency for plaintiffs seeking a remedy for police misconduct. The Article concludes with a recommendation that courts adopt and apply a general rule that facts supporting an affirmative defense shall be considered among the totality of facts and circumstances available to the arresting officer, and that such exculpatory facts shall be evaluated with the same level of scrutiny afforded inculpatory facts.