Under what circumstance is it appropriate to ask a passenger for identification?

Asking a passenger for identification is appropriate when there is a known driving violation by the driver because the traffic stop itself justifies a certain level of inquiry into the identities of all individuals in the vehicle. The rationale is based on the enforcement of laws concerning the driver’s compliance; if a violation is evident, the officer can seek to confirm the identity of all passengers for various reasons, such as ensuring there are no outstanding warrants or other legal issues associated with them.

In this context, identifying passengers can also enhance officer safety and help the law enforcement officer manage the situation more effectively. It is customary for officers to ensure that passengers are also not contributing to illegal activity or are complicit in unlawful behavior associated with the driving violation. Thus, when a specific violation is noted, the stop serves as a valid basis for inquiry into the passenger's identity as part of standard policing procedures.