...to explore how guns migrate from the so-called legitimate gun-distribution network to the hands of killers, robbers, and inner-city gangsters,"...
Yep, those migratory guns and their actions really need to be studied.
Do they migrate south in winter like birds do? Perhaps they actually hibernate until they can find a criminal to attach themselves to.
All mine were tagged by game wardens. I sometimes get a kick out of following them in a helicopter during their seasonal migration.