Interesting article about the Fairfax County PD identity systems.
http://www.findbiometrics.com/interviews/i/7547/
We currently employ a Datastrip model, but we’re looking at other models as well. The Datastrip Mobile AFIS is a fingerprint and a facial recognition system we use in the field. The Mobile AFIS is used by our patrol units, neighbourhood patrol units,— which are our bike-teams, gang units, narcotics units, fugitive section, crime scene section and crash reconstruction section. The circumstances of the encounter dictate the use of the device. It is used most often in a voluntary capacity; for example, the person to be identified does not have identification, or provides what is known to be fake documents. The officer will challenge them as to their true identity. The officer will then ask the individual to volunteer to use the mobile AFIS device to confirm their identity or provide some other proof of their identity. This works particularly well in situations where the person is under arrest for a traffic or summons releasable offense where they could be issued a summons and released if they could provide confirmation of their identification through a valid license or ID. If the subject has neither, they can volunteer to use the mobile AFIS to avoid having to be taken before a magistrate. If the subject is under arrest, then they just come with us anyway, and we go to a jail facility where we confirm their identity through our live-scan systems. But, when our personnel are out in the field, it is used as voluntary identification system.