Under the current policy, the sheriff's office holds all illegal immigrants for ICE. That includes those charged with felonies and misdemeanors.
ICE launched a nationwide program called Secure Communities last year that links its computers to the California Justice Department's fingerprint database. It allows the agency to monitor fingerprint data collected during the booking process. ICE then requests local law enforcement agencies to detain individuals they've identified being in the country illegally.
As of next month, Hennessey says his office will turn over only those illegal immigrants who are arrested for felonies, which is in compliance with San Francisco's sanctuary policy. Hennessey adds that state law does not require local counties to hold residents identified by ICE as undocumented immigrants, so he says his office is not violating any law.
The U.S. Justice Dept. says only states can opt out of the Secure Communities program, not individual law enforcement agencies.
Virginia Kice, a spokesperson for ICE, gave ABC7 News a prepared statement saying the sheriff's decision was "unfortunate."
"ICE detainers are an effective tool to ensure that individuals arrested on criminal charges, who are also in violation of U.S. immigration laws, are not released back into the community to potentially commit more crimes," Kice said.