By American Immigration Council

Over the past decade, an increasing number of states, counties, and cities have adopted a variety of policies intended to promote a greater level of trust and cooperation between local law enforcement and communities with sizeable immigrant populations, regardless of immigration status. These policies include offering English-language classes; issuing municipal identification documents and driver’s licenses to all residents; ensuring that immigrants have equal access to bail; establishing policies to make it easier for noncitizen victims of crime to obtain necessary documents from law enforcement agencies in order to pursue certain immigration relief; and training criminal prosecutors and public defenders on the immigration consequences of convictions and plea deals.  

One subset of these policies concerns a state’s or locality’s role in cooperating with federal authorities to enforce immigration law. These laws, policies, or resolutions are sometimes referred to as “sanctuary” policies, although no legal or standard definition of the term exists. There are many reasons jurisdictions adopt sanctuary policies, such as: a desire to protect public safety by allowing immigrants to work with police in reporting and investigating crimes without fear of retribution or potential deportation; allowing state and local governments to determine how they will prioritize and allocate their resources; and shielding local law enforcement agencies from liabilities resulting from local enforcement of federal immigration laws. 

Despite the nationwide debate, there is no one clear definition of what it means for a state or local government to adopt sanctuary policies. Sanctuary policies take many forms and generally fall into the following categories: 

• policies restricting the ability of state and local police to make arrests for federal civil immigration violations, or to detain individuals on civil immigration warrants;  

• policies prohibiting “287(g)” agreements through which Immigration and Customs Enforcement (ICE) deputizes local law enforcement officers to enforce federal immigration law; 

• policies that prevent local governments from entering into a contract with the federal government to hold immigrants in detention; 

• policies preventing immigration detention centers; 

• policies restricting the police or other city workers from asking about immigration status; 

• policies restricting the sharing of certain information on immigrants with the federal government; 

• policies restricting local police responses to federal immigration detainers; and 

• policies refusing to allow ICE into local jails without a judicial warrant. 

The common theme behind these categories is that under a sanctuary policy, state and local officials will limit their cooperation with federal immigration officials but do not actively prevent federal officials from carrying out their immigration enforcement duties. 

One of the most common forms of sanctuary policy is a restriction on holding immigrants in state or local jails following a “detainer” issued by ICE. A detainer is an official but nonbinding request from ICE that a state or local law enforcement agency maintain custody of an individual for up to 48 hours beyond the time the individual otherwise would have been released so that ICE can arrange to take over custody.  

Washington DC: American Immigration Council, 2025. 9p.

By Felipe Gon ̧calves Elisa and J ́acome Emily Weisburst

We study the role of victim reporting in the production of public safety. We examine the Secure Communities program, a crime-reduction policy that involved police in
detecting unauthorized immigrants and increased deportation fears in immigrant communities. We find that the policy reduced the likelihood that Hispanic victims report crimes to police and increased offending against Hispanics. The number of reported crimes is unchanged, masking these opposing effects. We show that reduced reporting drives the offending increase and provide the first elasticity of offending to victim reporting in the literature, calculating that a 10% decline in reporting increases offending by 7.9%.

Unpublished paper 2025. 95p.

Edited by Anniina Autero, Marcela de Moraes Batista Simão, Ilari Karppi

This open access book explores the use of technologies for urban safety and security. Rather than focusing on the technologies themselves, it provides and in-depth analysis of the complex urban transformations linked to the increasing integration of technical systems in the built environment. Interdisciplinary contributions explain how technologies can improve urban safety, whilst offering a broader discussion relative to urban, socio-economic and political factors. Against simplistic techno-solutionist ideas, the authors illustrate the role of technology as means to an end and show how technologies can widen our understanding of safety and security. Readers are introduced to issues relative to the practical implementation, development, and testing of urban technologies via numerous case studies from cities around the world.

Singapore: Palgrave Macmillan, 2025. 317p.

By Felipe Gonçalves, Elisa Jácome and Emily Weisburst

How does immigration enforcement affect public safety? Heightened enforcement could reduce crime by deterring and incapacitating immigrant offenders or, alternatively, increase crime by discouraging victims from reporting offenses. The researchers study the U.S. Secure Communities program, which expanded interior enforcement against unauthorized immigrants. Using national survey data, they find that the program reduced the likelihood that Hispanic victims reported crimes to police and increased the victimization of Hispanics. Total reported crimes are unchanged, masking these opposing effects. The researchers provide evidence that reduced Hispanic reporting is the key driver of increased victimization. Their findings underscore the importance of trust in institutions as a central determinant of public safety.

Evanston, IL: Northwestern University, 2024. 95p.

By Hannah Jones , Yasmin Gunaratnam , Gargi Bhattacharyya , William Davies , Sukhwant Dhaliwal , Kirsten Forkert , Emma Jackson and Roiyah Saltus

The 2013 Go Home vans marked a turning point in government-sponsored communication designed to demonstrate control and toughness on immigration. In this study, the authors explore the effects of this toughness: on policy, public debate, pro-migrant and anti-racist activism, and on the everyday lives of people in Britain. Bringing together an authorial team of eight respected social researchers, alongside the voices of community organisations, policy makers, migrants and citizens, and with an afterword by journalist Kiri Kankhwende, this is an important intervention in one of the most heated social issues of our time."

Manchester, UK: Manchester University Press, 2017. 204p.

By Pia Orrenius and Madeline Zavodny

Opponents of immigration often claim that immigrants, particularly those who are unauthorized, are more likely than U.S. natives to commit crimes and that they pose a threat to public safety. There is little evidence to support these claims. In fact, research overwhelmingly indicates that immigrants are less likely than similar U.S. natives to commit violent and property crimes, and that areas with more immigrants have similar or lower rates of violent and property crimes than areas with fewer immigrants. There are relatively few studies specifically of criminal behavior among unauthorized immigrants, but the limited research suggests that these immigrants also have a lower propensity to commit crime than their native-born peers, although possibly a higher propensity than legal immigrants. Evidence about legalization programs is consistent with these findings, indicating that a legalization program reduces crime rates. Meanwhile, increased border enforcement, which reduces unauthorized immigrant inflows, has mixed effects on crime rates. A large-scale legalization program, which is not currently under serious consideration, has more potential to improve public safety and security than several other policies that have recently been proposed or implemented.

Dallas: Federal Reserve Bank of Dallas, 2019. 19p.

By Nazgol Ghandnoosh and Josh Rovner

Starting from his first day as a candidate, President Donald Trump has made demonstrably false claims associating immigrants with criminality. As president, he has sought to justify restrictive immigration policies, such as increasing detentions and deportations and building a southern border wall, as public safety measures. He has also linked immigrants with crime through an Executive Order directing the Attorney General to establish a task force to assist in “developing strategies to reduce crime, including, in particular, illegal immigration, drug trafficking, and violent crime,” and by directing the Department of Homeland Security to create an office to assist and publicize victims of crimes committed by immigrants. By surveying key research on immigration and crime, this report seeks to enable the public and policymakers to engage in a more meaningful policy debate rooted in facts. Immigrants’ impact on public safety is a well-examined field of study.

Washington, DC: The Sentencing Project, 2017. 18p.