I don’t know if there is a factual answer to this, so here instead of GQ.
On another board, I’m having a bit of discussion surrounding California’s new status as a ‘sanctuary state’. The other guy is suggesting that it is/should be a felony for CA officials to not hold suspected/actual/alleged illegal aliens for ICE. I’m pretty sure that is wrong (his argument is aiding and abetting escape or something).
However, in discussing it, I suggested that, in the absence of a state/local law specifically empowering local law enforcement to hold people on purely Federal charges, that the detained person would have an argument that they have been kidnapped and/or falsely arrested and/or unlawfully detained.
I wouldn’t expect any such charge/civil suit to actually gain much traction, but is it a reasonable argument? I’m guessing that most states do have some sort of statute allowing local law enforcement to hold people on a Federal warrant or equivalent, and that California has presumably carved out an exception in the case of undocumented aliens?
Kidnapping, for instance, is a federal offense, and I would be surprised if a judge took complaints of false arrest at all seriously if the kidnapper were picked up by the local police.
Kidnapping is also a state crime - and per the link, is usually prosecuted at the state level. Which surprised me, after years of TV harping on it being a Federal crime.
Feds get involved in kidnapping cases quite often, as they often involve the kidnappers crossing state lines, this is why they are often involved, and probably why Shodan mistakenly seems to think they had exclusive jurisdiction.
But in a case like this, no, the feds would have no jurisdiction whatsoever. It would be entirely up to the state.
So, a state or local judge, elected by the same people who elected the representatives that passed legislation disallowing the police to arrest people and hold them for ICE would most certainly not look favorably upon law enforcement officers thumbing their nose at the law, and illegally detaining people.
If a suspect is arrested for murder, what is the procedure to establish his identity? Before he can be prosecuted, does he have to prove his identity by some paper form? What if he refuses? In the USA, if confronted by the police, you are required to verbally state, on request, your name and I believe your address. No more. So even if the suspect is charged with a serious felony, the police have no grounds to demand photo ID, birth certificate, or anything proving that he who he says he is.
By extension of this, the police may, nay must, ask him no questions concerning his citizenship, and therefore cannot know the immigration status of a suspect in their custody. And therefore not in violation of any federal law concerning the holding of any suspected/actual/alleged illegal aliens. The suspect is immune to that determination by the Federal’s own Constitution.