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Police, Jails, and Immigrants: How Do Immigrants and the Immigration Enforcement System Interact with Local Law Enforcement?

In recent years, one contentious component of the immigration debate has been that of so-called sanctuary cities: municipalities or local law enforcement jurisdictions that have adopted policies that limit their cooperation with Immigration and Customs Enforcement (ICE). While both sides have made the role of state and local law enforcement agencies the debate’s core issue, misconceptions about these agencies’ operations and their interaction with the immigration enforcement system persist.

The Bipartisan Policy Center’s review of law enforcement agencies in Atlanta, Austin, Charlotte, Denver, and Los Angeles shows that the actual operation of local law enforcement agencies and their work with immigration enforcement agencies is more complex and nuanced than is often reported in the public debate.

The review found that:

“Local law enforcement” comprises a range of agencies that often operate in overlapping territorial jurisdictions established by their state’s constitution.

  • Denver: The city of Denver is the county seat of Denver County, Colorado and the municipal Denver Police Department oversees day-to-day crime, traffic, and enforcement while the Denver County Sheriff Department oversees two separate jail facilities and the district and county courts. The consolidated City and County of Denver also has one Department of Public Safety which oversees both the Police Department and the Sheriff Department. Although these law enforcement agencies work within a complex multitier system, the jurisdictional divides are nested and clearly organized for clear cooperation across the Denver metropolitan area.
  • Austin: Under the jurisdiction of the City of Austin, the Austin Police Department is the main municipal law enforcement agency. In addition to being in Travis County, the city is also part of Williamson, Hays, and Bastrop counties, and Austin Police Department officers operate in the same jurisdictions as the sheriff’s departments for these counties throughout the greater Austin area, compounding the difficulty of assigning one local law enforcement body as wholly representative for the entire area.

Local law enforcement agencies often have different immigration enforcement policies and increasingly state legislatures are weighing in.

  • Austin: Travis County Sheriff Sally Hernandez reversed her predecessor’s active cooperation with ICE and allowed the county’s officers to reject detainer requests unless for serious crimes. While the Austin Police Department has not adopted a formal policy, Austin City Police Chief Brian Manley has stated publicly his officers would work with federal immigration agencies only if the case has “a criminal nexus.” In response to Sheriff Hernandez’s decision, the Texas state legislature passed Senate Bill 4 in May 2017, an anti-sanctuary city bill that forces localities to cooperate with ICE and bans sanctuary policies such as Travis County’s measure.
  • Los Angeles: The city council and Los Angeles Police Department have adopted orders and directives that limit their employees from gathering information about an individual’s legal status and cooperating with ICE activities. However, the Los Angeles County Sheriff’s Department has allowed ICE agents into its jails even though the Los Angeles County Board of Supervisors voted to limit this access in 2015. In October 2017, the state’s legislature passed Senate Bill 54, a statewide sanctuary policy that prohibits state and local law enforcement from using their resources to share information with federal immigration agencies.

County sheriff’s offices operate most local jails in the country and respond to ICE detainer requests rather than officers who work for the city’s local police departments.

  • Jails are usually county-level confinement facilities that local law enforcement agencies such as sheriff’s offices or departments of correction operate for individuals awaiting trial or sentencing, or whose inmates are generally sentenced to a term of less than one year.
  • Sheriff’s offices that operate jails, not necessarily the local police departments, primarily interact with ICE on immigration detainers or “ICE holds” where ICE requests a local jail to hold individuals up to 48 hours beyond their scheduled release date from the facility.
  • Sheriff’s offices can also join ICE’s 287(g) program that allows local law enforcement officers to take on additional immigration enforcement duties such as checking an individual’s immigration status or issuing immigration detainers and Notices to Appear within the jails.
    • County agencies have adopted or rejected these agreements for different reasons.
      • The Travis County (Texas) Sheriff’s Office allows their officers to reject requests to generate more support from the area’s immigrant community.
      • The Mecklenburg County (North Carolina) Sheriff’s Office has maintained a 287(g) agreement with ICE since 2006 to protect its citizens by identifying undocumented immigrants who commit crimes.


These examples represent a small sample of the local law enforcement jurisdictions that operate across the United States, but they show how the term “sanctuary cities” elides over the manner that law enforcement agencies can operate in a given region where cities, counties, states, and these agencies have adopted a range of policies related to cooperation with immigration enforcement.

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