Does Deporting Immigrants Lower Crime? Evidence from Secure Communities

The Issue:

The goal of reducing crime has been cited as one justification for policies that increase the government's ability to deport immigrants. But there are different — and conflicting — ways in which increasing deportations could impact crime. If immigrants targeted for deportation are more likely to be criminals, for instance, then deporting them could reduce local crime. Alternatively, if an increased emphasis on immigrant deportations ties up police resources that could be deployed more effectively, then such a policy could actually result in increases in crime rates. The Secure Communities program, which led to a large increase in deportations in the U.S. between 2008 and 2014, offers an opportunity to study the impact of increased deportations on local crime and police effectiveness.

There are different — and conflicting — ways in which increasing deportations could impact crime.

The Facts:

• Between its introduction in 2008 and temporary suspension in 2014, the Secure Communities program led to over 450,000 deportations. In 2008, the Department of Homeland Security launched Secure Communities as a tool to engage the resources of local police in federal immigration enforcement efforts by screening anyone booked into jail, no matter the reason, for immigration violations. Prior to this program, immigration authorities and local law enforcement would collaborate on a case-by-case basis and police only checked the immigration status of a small fraction of arrested persons. Under Secure Communities, police had to check the fingerprints and bio-metric information of any arrested person against an immigration database. Immigration and Customs Enforcement (ICE), the federal immigration enforcement agency, could take custody of any person found to have violated immigration law, have local authorities hold them for an additional 48 hours, and potentially begin deportation proceedings. Non-citizens can be deported for a variety of reasons. For a person legally present in the country, felony convictions can result in deportation. For undocumented immigrants, even minor offenses can trigger deportations, as can an arrest resulting in no charges or no criminal conviction. 
• Deportations could reduce crime if those deported are serious criminals. Despite the fact that jails were the initial contact between immigrants and potential deportation proceedings under Secure Communities, not all deportations removed serous criminals. Over 15 percent of deportations were for people without any criminal conviction; minor offenses, such as immigrations violations and traffic offenses, make up another 30 percent of deportations. Additionally, if people who commit immigration violations are also more likely to commit other offenses, programs that provide immigration information to the police may help local law enforcement prevent crimes. However, academic studies find little correlation between immigration and crime rates in the United States. Most studies find that immigrants are less likely to commit crimes and less likely to be incarcerated than native-born individuals of similar gender, age, and education. Studies have also found that undocumented immigrants have lower conviction and arrest rates than natives.
• The Secure Communities program could also impact police efficiency and police resources by altering how local law enforcement allotted limited resources and changing the demands of those resources. Local and state authorities undertook the cost of detaining people prior to ICE taking custody. If few of the people detained under Secure Communities were serious criminals, then the procedures and costs involved in detaining them may divert resources from where they can be more productive in fighting crime. In addition, involving local authorities in immigration enforcement could have an effect on police effectiveness by changing the interactions between the police and local communities. Immigrants are also victims of and witnesses to crime. A greater focus on deportation could make immigrants less likely to cooperate with authorities and less likely to report certain kinds of crime. Alternatively, if immigrants — especially undocumented immigrants — are involved in a large fraction of crimes, then the ability to detain them may be a tool for the police to pressure them and to solve crimes, ensuring more arrests of criminals.
• The large increase in deportations and Secure Community’s staggered start date across counties allows us to estimate the effect of the increased deportations. Due to resource constraints, the implementation of Secure Communities was staggered — beginning in counties close to the Mexican border in 2008 and expanding to the entire country by January of 2013. As a consequence deportations relative to population increased over time and their prevalence spread from border counties towards the rest of the country as well (see maps). In our research we take advantage of the variation in timing across counties from this staggered roll-out to identify the effects of the policy. In addition, the implementation of the policy would be expected to have a larger effect in areas with a larger share of undocumented immigrants, since they are the most likely to face deportation. 
• Did more intense immigration enforcement, as measured by deportations relative to population, decrease crime rates for violent or property offenses? Our study finds that an increased rate of deportations did not lower crime. Increased deportations per population had no significant effect on violent crime. And, in the case of property crime, deportations had the opposite effect: we find that an increase in deportation rate resulted in a higher rate of property crime — however, the magnitude of this effect was quite small. To put this in perspective, the areas that saw the largest increases in deportation were those with large concentrations of undocumented immigrants were ICE deported about 10% of the undocumented in a given year, accounting for about 0.2% of the total population. Our estimates suggest that a 0.2% increase in the deportation rate would increase property crimes by 205 per 100,000 persons relative to an average of 4534 property crimes per 100,000 people per year. This result is inconsistent with the notion of deportations removing criminals and thus reducing crime. 
• Do increased deportations impact local police's ability to solve outstanding crimes? One way to measure police efficiency is to look at the clearance rate, which is the number of crimes cleared by arrest, relative to all the reported and confirmed crimes. We find that increased deportations did not have a significant effect on clearance rates for violent crimes and had a very small effect on the clearance rate for property crimes. A large increase in the local deportation rate of 0.2 percentage points resulted in an increase of 0.04 percentage points in the clearance rate for property crimes (relative to an average of 18%). These are negligible effects, supporting the notion that increased enforcement does not result in efficiency gains for local law enforcement.