Hassle.

• Author: Bambauer, Jane
• Position: Individualization in police search to minimize hassle burden on the innocent - Abstract through II. Hassle A. A Compact Model for Criminal Investigations, p. 461-487

Before police perform a search or seizure, they typically must meet the probable cause or reasonable suspicion standard. Moreover, even if they meet the appropriate standard, their evidence must be individualized to the suspect and cannot rely on purely probabilistic inferences. Scholars and courts have long defended the distinction between individualized and purely probabilistic evidence, but existing theories of individualization fail to articulate principles that are descriptively accurate or normatively desirable. They overlook the only benefit that the individualization requirement can offer: reducing hassle.

Hassle measures the chance that an innocent person will experience a search or seizure. Because some investigation methods meet the relevant suspicion standards but nevertheless impose too many stops and searches on the innocent, courts must have a lever independent from the suspicion standard to constrain the scope of criminal investigations. The individualization requirement has unwittingly performed this function, but not in an optimal way.

Individualization has kept hassle low by entrenching old methods of investigation. Because courts designate practices as individualized when they are costly (for example, gumshoe methods) or lucky (for example, tips), the requirement has confined law enforcement to practices that cannot scale. New investigation methods such as facial-recognition software and pattern-based data mining, by contrast, can scale up law-enforcement activities very quickly. Although these innovations have the potential to increase the accuracy of stops and searches, they may also increase the total number of innocent individuals searched because of the innovations' speed and cost-effectiveness. By reforming individualization to minimize hassle, courts can enable law-enforcement innovations that are fairer and more accurate than traditional police investigations without increasing burdens on the innocent.

TABLE OF CONTENTS INTRODUCTION I. Individualized Suspicion Amiss A. The Snowflake Theory B. The Felt Belief Theory C. Suspicious Conduct Theories D. Crime-Out Investigations E. Ending the Status Quo II. HASSLE A. A Compact Model for Criminal Investigations B. The Importance of Hassle C. Individualization Reduces Hassle D. Other Instincts Explained 1. Odd but Legal Behavior 2. A Preference for More Factors 3. Undefined Suspicion Standards 4. The Search for Distributional Justice III. THE FUTURE OF SUSPICION A. More Open and Honest Experimentation B. Fewer Vague Narratives C. More Randomness D. Objections CONCLUSION INTRODUCTION

A police officer has submitted an application to a magistrate judge requesting warrants to search every dorm room in the Harvard College residence halls for illegal drugs. To establish probable cause, the officer furnished a copy of a recently published study about student life at Harvard. The study is methodologically sound and concludes that 60% of the on-campus dorm rooms contain illicit drugs.

Naturally, the magistrate judge will deny the application, but why? While probable cause is not defined as a precise probability, we are told that the standard sits below "more likely than not." (1) A 60% likelihood of finding drugs in any given dorm room should easily clear the bar.

The textbook response to this Harvard dorm hypothetical, a variant of a puzzle posed by Orin Kerr, (2) is that the suspicion stemming from a statistical study is not individualized. The evidence is not tailored to each Harvard student whose home is to be searched. The study offers only probabilistic evidence. No matter how great the chances of finding drugs may be, lack of individualization presents a disqualifying flaw. (3)

Individualized suspicion therefore consists of two distinct prongs. The police must have suspicion--a fairly good chance of finding evidence of a crime--and they also must have individualization. This Article explores the second prong, the individualization requirement, in search of a principled distinction between particularized evidence and evidence that is probabilistically sufficient but constitutionally flawed.

The predominant justification for the individualization requirement appeals to a rejection of cold calculations and group-based generalizations, but this appeal falls flat with a little scrutiny. Police and judges must always resort to rough estimates of the conditional probability that a suspect has engaged in crime. Whether police use a collection of details (a partially corroborated tip and unusual travel habits) or just one important detail (a weaving car or a tattoo matching a victim's description), they ultimately must ask whether the innocent explanations for the observations are much more probable than the illicit ones. (4) Indeed, even vocal opponents of actuarial policing have acknowledged that all suspicion is built from probabilistic inferences. (5)

Moreover, the distinctions that we intuitively draw between individualized and merely mathematical suspicion get the public policy backwards. Because the investigation methods approved by courts usually rely on the observations and perceptions of police, the "particularized" evidence is likely to be biased, error prone, and disproportionately aimed at poor and minority residents living in higher-crime areas. (6) Subjective factors like a suspect's "nervousness" or "furtive movements" can be imagined or, worse still, manufactured through deceit. (7) And the long, detailed narratives that courts have come to expect from police in order to satisfy particularization requirements are so inconsistent that they risk diluting the suspicion requirement. (8) Individualization seems to be intellectually bankrupt and morally hazardous.

Nevertheless, our fumbling with the notion of individualization performs latent but valuable work. Given that all evidence is probabilistic, the virtue of individualization has little to do with the nature of probabilistic calculations. It doesn't even have much to do with the particular suspect. Instead, individualization protects everybody else from the potential costs of law-enforcement investigations. The techniques courts and scholars accept as individualized exclude most of the population from the practical likelihood of police intrusions. Because they rely on perceptions of police officers or on happenstance like tips, the traditional methods cannot scale. Actuarial methods can.

This Article argues that the purpose of individualization is to minimize hassle. Hassle is the chance that the police will stop or search an innocent person against his will. (9) After all, while we may not all be Harvard students, we do inevitably engage in activities that predict a high chance of crime. We pace. We circle the block. We travel with bulky or light luggage. And we attend Phish concerts. If the police were able to act on all reasonably predictive statistical models en masse, we would experience an inappropriate and dramatic increase in suspicion-based searches and seizures. The individualization requirement constrains hassle by ensuring that an innocent person is unlikely to be stopped or searched even if he seems suspicious from time to time.

The twin prongs of individualized suspicion--suspicion and individualization--ought to be loosely guided by hit and hassle rates. A hit rate is the probability that a stop or search will uncover evidence of a crime. Hit rates measure suspicion and must meet the relevant standard (reasonable suspicion for Terry stops and probable cause for full-blown searches and seizures). (10) Hassle rates, by contrast, measure the probability that an innocent person within the relevant population will be stopped or searched under the program. Hassle rates speak to individualization. If a program is likely to cause too much hassle, the police have not sufficiently narrowed the scope of the investigation, no matter how high the hit rate may be. Hassle rates keep track of the societal costs of criminal investigations, and hit rates ensure that the costs are justified.

Courts and scholars have already grown accustomed to examining hit rates when data are available. (11) When they are not, courts and scholars have used common sense and experience to estimate the same thing: whether the police had a decent shot of uncovering incriminating evidence during a stop or search. But hit rates alone cannot keep the government in check. Hassle rates are also crucial to the Fourth Amendment's protection. For rare crimes, like murder, a high hit rate can guarantee a low hassle rate. But for more common crimes, such as drug possession, (12) an additional constraint must curb governmental intrusions. At a higher level of abstraction, hit and hassle perform the delicate balancing of interests that the Fourth Amendment demands.

Hassle explains many of the instincts already embedded in the individualization precedent. For example, it explains the courts' consistent preference for police narratives chock-full of detail, even when each additional detail does not contribute much to the amount of suspicion. (13)

Hassle can also explain the Harvard dorm room hypothetical. If an officer requests warrants to search the dorms of all 6,000 students living in Harvard residential halls, we know ex ante that approximately 2,400 of them will not have illegal drugs. In one fell swoop, the police will have imposed significant costs on the innocent population in the Harvard and Cambridge communities.

On the other hand, the Harvard dorm room hypothetical also commands attention to a lost opportunity. If the warrant were issued, the Cambridge police could have greater success searching a Harvard student and could create inroads for criminal enforcement within elite communities otherwise immune to the enforcement of minor criminal laws. But the dominant understanding of individualization will push the police out of the Harvard dorms and back into the homes and pockets of the poor...