An inspection system based upon an enclosed conveyance such as a van, capable of road travel, for inspecting persons or objects. The conveyance is characterized by an enclosing body, or skin. A source of penetrating radiation and a spatial modulator for forming the penetrating radiation into a beam, both contained entirely within the body of the enclosed conveyance, irradiate the person or object with a time-variable scanning profile. A detector module generates a scatter signal based on the scatter of penetrating radiation. A proximity sensor may be employed to generate a relative motion signal based on a relative disposition of the conveyance and the inspected object. An image is formed of the contents of the object based in part on the scatter signal and the relative motion signal. A detector, which may be separate or part of the scatter detector module, may exhibit sensitivity to decay products of radioactive material.