Sanctuary city policies linked to lower crime rates in recent years

Today, nearly 250 local jurisdictions in the U.S., including 5 states, have established sanctuary policies indicating they will not automatically honor Immigration and Customs Enforcement Agency (ICE) detainer requests. In a study published in Contemporary Economic Policy, researchers used data from the Federal Bureau of Investigation Uniform Crime Reporting Program to estimate the relationship between sanctuary policies and various categories of crime at the county level from 2010–2016.

Local jurisdictions that introduced sanctuary policies by placing limits on cooperation with ICE experienced decreases in crime relative to counties that continued to comply with ICE detainer requests. Investigators estimated that implementing a sanctuary policy in a county was associated with 17.9 fewer violent crimes per 100,000 residents each year.

"A wave of sanctuary policies implemented in 2014 provided us with a shock that we leveraged to establish an association between sanctuary policies and crime. Our results are consistent with the hypothesis that local sanctuary policies can increase the effectiveness of law enforcement and decrease crime costs," said corresponding author Jesse Burkhardt, Ph.D., of Colorado State University.