Secure Communities is mandatory, over objections of San Francisco and others
The Department of Homeland Security's Secure Communities program collects the fingerprints of those charged with crimes by localities and checks them for immigration violations. Now, a few illegal immigration-supporting communities are finding out that, despite a previous statement from DHS implying otherwise, there's no opt-out. Localities already send such fingerprints to the FBI and the DHS gets them from the latter source and not from the former.
A senior ICE official, speaking on the condition of anonymity because he was not authorized to talk about the involuntary nature of the program, said: "Secure Communities is not based on state or local cooperation in federal law enforcement. The program's foundation is information sharing between FBI and ICE. State and local law enforcement agencies are going to continue to fingerprint people and those fingerprints are forwarded to FBI for criminal checks. ICE will take immigration action appropriately."
The only way a local jurisdiction could opt out of the program is if a state refused to send fingerprints to the FBI. Since police and prosecutors need to know the criminal histories of people they arrest, it is not realistic for states to withhold fingerprints from the FBI - which means it is impossible to withhold them from ICE.
Those who wanted to opt-out are: Santa Clara County, Arlington County, Washington DC, and, of course, San Francisco. The article also quotes Walter Tejada of Arlington County as being upset, which is a good thing. And, this will one of the few positive steps Janet Napolitano has taken, just as long as it is actually mandatory in practice.