"RAS?" Didn't feel like looking that one up. I'm sure it would be obvious ( ) if I had more coffee in me.
It's an inaccurate acronym. It stands for "Reasonable Articulable Suspicion." Unfortunately, there ain't no such critter. The law on which it's based doesn't refer to "reasonable articulable suspicion." It goes back to the case of
Terry v. Ohio, which was decided by the Supreme Court. To paraphrase the court, in order to effect a custodial detention a police officer must have "a reasonable suspicion
based on clearly articulable facts that a crime has been committed, is being committed, or is about to be committed."
So, according to the Supremes, it is not the suspicion that must be reasonably articulable, it is the facts underlying the suspicion. But, the Internet persists in using "RAS" as if it means something.