A volume interrogation system can use an accelerated beam of charged particles to interrogate objects using charged-particle attenuation and scattering tomography to screen items such as electronic devices, packages, baggage, industrial products, or food products for the presence of materials of interest inside. The apparatus, systems, and methods in this patent document can be employed in checkpoint applications to scan items. Such checkpoint applications can include border crossings, mass transit terminals (subways, buses, railways, ferries, etc.), and government and private-sector facilities.