Two years ago, as others in California were limiting cooperation with federal immigration agents, the Fresno County Sheriff’s Department welcomed them into its jail.

Sheriff Margaret Mims gave U.S. Immigration and Customs Enforcement unrestricted access to databases and private rooms to interview inmates. She reorganized release times so agents could easily pick up people who had served their sentences.

The policy sparked outrage among immigrant rights groups, who called it a pipeline from incarceration to immigrant detention.

“We are not anti-immigrant for working with ICE,” Mims said in defense of the approach. “We are anti-criminal activity.”

That belief is held by many of California’s 58 county sheriffs who will be on the front lines of implementing the landmark “sanctuary state” law, which Gov. Jerry Brown signed last month. It takes effect on Jan. 1, the Los Angeles Times reports.