It is intuitively crazy to think that speaking Spanish in Montana is evidence of a crime. Still, we will have to wait to see what the courts rule, if it goes that far. We should start with Terry v. Ohio, 392 U.S. 1, which found that
in justifying the particular intrusion, the police officer must be
able to point to specific and articulable facts which, taken together
with rational inferences from those facts, reasonably warrant that
intrusion. The scheme of the Fourth Amendment becomes meaningful only
when it is assured that, at some point, the conduct of those charged
with enforcing the laws can be subjected to the more detached, neutral
scrutiny of a judge who must evaluate the reasonableness of a
particular search or seizure in light of the particular circumstances.
And, in making that assessment, it is imperative that the facts be
judged against an objective standard: would the facts available to the
officer at the moment of the seizure or the search "warrant a man of
reasonable caution in the belief" that the action taken was
The Montana officer did "articulate" a reason, in saying "Ma’am, the reason I asked you for your ID is because I came in here and I saw that you guys are speaking Spanish, which is very unheard of up here". In articulating an excuse, the officer has not passed the test of providing "rational inferences from those facts". Of course, the law also does not require an officer to explain his reasoning to the suspect. In Terry, the officer
had never seen the two men before, and he was unable to say
precisely what first drew his eye to them. However, he testified that
he had been a policeman for 39 years and a detective for 35, and that
he had been assigned to patrol this vicinity of downtown Cleveland for
shoplifters and pickpockets for 30 years. He explained that he had
developed routine habits of observation over the years, and that he
would "stand and watch people or walk and watch people at many
intervals of the day." He added: "Now, in this case, when I looked
over, they didn't look right to me at the time."
The reasoning in these cases is quite parallel: an appeal to a subjectively felt unusualness of a circumstance. There may be a factual dispute over how often Spanish (or Nakhota) is spoken in public in Havre, but we may assume that Spanish is spoken much less often than English. Still, a well-grounded belief that a person speaks Spanish (let us stipulate that it is fluent) is not at all evidence that a person has committed a crime. The inference is no more rational than McFadden's inference from "I don't know you" to "You must be a criminal".
See US v. Brignoni-Ponce, 422 U.S. 873, which held that
an officer whose observations lead him reasonably to suspect that a
particular vehicle may contain aliens who are illegally in the country
may stop the car briefly, question the driver and passengers about
their citizenship and immigration status, and ask them to explain
suspicious circumstances... To allow roving patrols the broad and
unlimited discretion urged by the Government to stop all vehicles in
the border area without any reason to suspect that they have violated
any law, would not be "reasonable" under the Fourth Amendment...The
Fourth Amendment therefore forbids stopping persons for questioning
about their citizenship on less than a reasonable suspicion that they
may be aliens.
The court has
refused to find that Mexican ancestry alone supported such a "founded
Speaking Spanish is as much evidence of foreign ancestry as speaking English is (referring to the Nakhota situation, ethnic Nakhota speak English all the time, but they do not have foreign ancestry). See also US v. Manzo Jurado
Given...inability to speak English, proximity to the border, and
unsuspicious behavior - law enforcement lacked reasonable suspicion
that Appellant and his co-workers were in this country illegally.
Moreover, the Manzo Jurado event took place in Havre MT. So the factual question of whether hearing Spanish spoken in Havre is already on the record. Not only is it spoken in Havre, it is spoken by an individual who spoke no English, and it was found by the court to not constitute reasonable suspicion.