In his post below, my friend and co-blogger writes that there is only one sentence of Arizona v. United States that you need to know to answer whether federal law preempts the new state Texas immigration enforcement bill.  Here’s the sentence:

Josh reads that as indicating that Arizona does not clearly conflict with the Texas law.  On his reading of the sentence, this is a question left open by Arizona, with Texas fairly raising an interstitial question ripe for litigation that could go either way.

But I don’t think that’s what the sentence says or means.

The power to detain a person to investigate a crime based on mere “reasonable suspicion” is just a power to very temporarily detain them.  It’s a Terry stop authority, giving officers, say, 20 or 30 extra minutes to check out what is going on.  That power does not allow the government to detain someone for much more than that time, or to bring them to a new place.  Under Dunaway v. New York, that kind of step is an arrest as a matter of Fourth Amendment law, and that requires probable cause.

As I read that one sentence, all it did was leave  open whether a state is allowed to add on that extra 20-30 minutes or so to investigate an immigration offense.

I’m not an expert in the new Texas law, but it does not seem to be a Terry stop law.  It appears to authorize arrests, which is a different ball of wax in the law of criminal procedure.  As I recall, arrests were dealt with in another part of the Arizona decision,  Section IV(C), which ruled that the Arizona law allowing arrests for committing removable offenses was preempted.

If we’re looking for the one sentence from Arizona to read on that issue, this one seems particularly relevant:

Of course, I wouldn’t just read that one sentence.  But Section IV(C) seems like an important section to focus on, not the one sentence about Terry stops.