When deciding whether a baseball player is likely to get a hit, we look at his history of success at the plate. When deciding whether to listen to the advice of a stock analyst, we look at whether the prices of her past recommendations rose or fell. But when police officers claim that they have probable cause to believe a certain location contains evidence of a crime, we do not look at whether they have been right or wrong when they have made the same claim in the past. This is a mistake. Law-enforcement-search success rates vary widely, even when the same legal standard applies. Searches pursuant to warrants issued on a probable cause standard recover evidence at very high rates, usually exceeding 80%. By contrast, warrantless searches, even when officers allege they have probable cause, succeed at far lower rates, recovering evidence as infrequently as 12% of the time. Similarly, some officers are far more successful than others when they conduct probable-cause searches. Some almost never recover evidence; some almost always do. What role should these different success rates play in probable-cause analysis? The current answer is none. Judges are not presented with the success rates of the law enforcement officers who appear before them. I argue that law enforcement should be forced to present success-rate data to judges when making probable-cause claims and judges should be allowed to consider the data when deciding whether to issue a warrant or approve a previously conducted search. These success rates capture information not currently analyzed in the search process and their addition would improve the accuracy of probable-cause decisions. Most significantly, we would learn private information in the possession of law enforcement that is not currently presented to judges.
Texas Law Review
Max J. Minzner,
Putting Probability Back into Probable Cause,
Texas Law Review
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