Mass Arrests & The Particularized Probable Cause Requirement

Three Supreme Court cases—United States v. Di Re, Ybarra v. Illinois, and Maryland v. Pringle—established the need for individualized or particularized probable cause in multiple-suspect arrests and searches. These three Supreme Court decisions have been used by plaintiffs seeking to sue police departments and municipalities under 42 U.S.C. § 1983 for civil rights violations stemming from mass arrests unsupported by probable cause. Oddly enough, these decisions have also been relied upon by defendants who allege that the law is unclear when it comes to particularized probable cause and multiple-suspect arrests. This Article seeks to carefully examine the history of mass arrests in America and analyze the probable cause requirement of the Fourth Amendment along with existing federal cases on multiple-suspect, group, and mass arrests, to demonstrate that the jurisprudence in this area is settled and clear. The Fourth Amendment’s probable cause analysis is and should be no different for individual arrests than for high-volume arrests.