[KyJim]

Terry still requires a reasonable suspicion of a crime before the officer is allowed to conduct even a cursory search, and that search is ONLY for the limited purpose of determining if the subject is armed. The officer is then entitled to take temporary custody of a sidearm "for officer safety." We agree to that point.

Here, the traffic violation supplies the reason for the stop under Terry. There does not have to be reasonable suspicion of a separate crime to conduct a limited search for weapons during a traffic stop. There does have to be reasonable suspicion a person is armed and dangerous.

First, a serial number is not "in plain sight" -- you have to look for it.

Simply having to turn your eyes toward an object or shine a flashlight on it does mean the object is not in plain view. Plain view just means it is not hidden from view; i.e., not in a closed bag or glove box.

[T]here is nothing about a serial number by itself, absent other contributing factors (which, under the rules set by Terry, must be "clearly articulable), to generate a reasonable suspicion that the gun is stolen. Accordingly, calling in the serial number to check it is an unconstitutional search.

But once the officer has the serial number, due to consent and plain view, there is no further search done by running the serial number. There does not have to be any suspicion the gun is stolen.

It is analogous to a police officer who decides to run a license plate of a car for no particular reason other than he or she is bored. The number is in plain view and running the plate number is not a search. Maybe it violates department procedure, but it's not unconstitutional.

Do they need reasonable suspicion the individual is armed and dangerous? Or just that a crime, any crime, has been committed? As I understood it, the fact that a person was pulled over for a traffic infraction was reasonable suspicion enough that a crime was committed that anyone- driver, passenger etc- were fair game for a terry stop pat down and disarming?

Terry requires reasonable suspicion of both a crime (satisfied by a traffic violation) and reasonable suspicion a person is armed and dangerous. In the Johnson case, the court said: "To justify a patdown of the driver or a passenger during a traffic stop, however, just as in the case of a pedestrian reasonably suspected of criminal activity, the police must harbor reasonable suspicion that the person subjected to the frisk is armed and dangerous." Arizona v. Johnson, 555 U.S. 323, 327 (2009) (emphasis added). This is not a direct holding of the court but I think it is pretty authoritative.

However, I think in many cases that if there is reasonable suspicion one of the persons is armed and dangerous, his or her traveling companions may also be armed and dangerous. It is a highly fact intensive inquiry and judges may come to different conclusions.