Arizona's new immigration enforcement statute has reignited the national debate on racial profiling. Critics of the new law, which allows police officers to determine the immigration status of any person legally stopped or arrested for any other reason, worry that it will lead to many more arbitrary stops of Latinos in Arizona.
That's a real concern even if the stops don't lead to arrests, because of the ill will that stops cause when they seem arbitrary and when police treat people who are stopped with disrespect. There's a better, even-handed way to identify illegal immigrants: checkpoints.
To understand the costs of arbitrary stops, consider street policing in New York City. New York law lays out highly structured rules that the cops must follow when making a stop. Yet for the last six years, an average of about 500,000 people have been stopped each year in the city. Four-fifths are black or Latino men. Many of them are stopped 10 times or more per year. And yet police rarely pursue charges. That's right: Nearly all of the young men stopped in New York City are never arrested.
Why should we care about lots of lawful stops that don't lead to arrest? Research shows that people who are stopped react more to how they feel they were treated by the police than they do to whether they are arrested. It sounds counterintuitive, but it's not. Basically, people care about being treated with dignity, and they also want to believe that the officer's decision to stop them was unbiased. They want cops to be polite, explain their actions, and use honorifics. They also typically look for signs that the basis of a stop was fair.
Perceptions of good treatment and fairness are the foundations of procedural justice, which matters a great deal in civil society. A robust body of social-science evidence from around the world shows that people are more likely to voluntarily obey the law when they believe that authorities have the right to tell them what to do. In fact, people are more motivated to comply with the law by the belief that they're being treated with dignity and fairness than by fear of punishment. When police generate good feelings in their everyday contacts, it turns out people also are motivated to help them fight crime. All of this leads to lower crime rates.
This brings us back to Arizona. Formal rules and actions that apply to everyone can signal fairness in a way that highly discretionary tactics, like the ones in the state's new law, do not. We can predict that if the new law leads to more police stops that Latinos and other Arizonans see as negative and biased, they will also see the police as less legitimate. Legitimacy apparently matters to the Arizona police, too. One officer in the state has already filed a lawsuit challenging the constitutionality of the law, making clear that he does not want to enforce it. Others have openly vowed to resist it.
Laws like Arizona's give individual police officers the discretion to pick and choose whom to stop on the basis of suspicion. Suspicion-based stops are legally justified when an officer correctly (or correctly enough) identifies or targets a potential offender. The problem is that according to the Supreme Court, even vague criteria count, such as "furtive movements" that supposedly indicate crime, or "Latino appearance" along with scuffed working boots that supposedly indicate illegal immigrant status. This is a bad idea because when stops are based on suspicion, police are more likely to view each person they stop as a wrong-doer, which means they're more likely to create ill will by being rude. Arizona adds to the incentive for indiscriminate stops by allowing citizens to sue police for not enforcing the law "enough."
If Arizona truly wants to identify undocumented aliens in a way that does not undermine legitimacy, it should try randomized checkpoints. Checkpoints are widely used by police to enforce drunk-driving laws and other routine safety checks—such as seat belt laws—that save lives. Police can do a good job finding offenders without having to play their hunches. Policing agencies are required to have a good reason to set up a checkpoint, of course. But once a checkpoint is set up, individual officers don't need to exercise their discretion. In fact, they can't under constitutional law. In the absence of discretion, the harm of being publicly targeted dissipates. And when officers don't need to invest in looking for individual offenders, but rather stop people on a routinized basis, they treat them equally and—we can hope—with more respect. (Update, May 24: Thanks to a reader who points out that Arizona already has two permanent checkpoints on Interstate 8 and Interstate 19 as well as flying checkpoints in Cochise County. These differ both in substance and spirit from our idea of randomized checkpoints that move from place to place.)
Checkpoints promote the virtue of evenhandedness. They spread the burden of law enforcement more widely, so that one group does not bear the brunt of it alone. And they tend to attenuate the connection between a police stop and wrongdoing. In the end, checkpoints allow law enforcement agencies to enforce the law in a way that, if done well, keeps us all safer.