Noninvasive polygraph technology based on optical analysis

A system and method for unobtrusively and noninvasively subjecting a living subject to tests for the purpose of determining whether that subject is truthful or is under stress, or both. A series of radiation pulses, preferably infrared laser pulses, is directed by a lidar transceiver toward the subject-which returns (e.g. reflects or scatters) the pulses back to the transceiver, which time-resolves that return to segregate and isolate phenomena at, within or in front of the subject's skin. The transceiver is connected to an information processing device capable of determining various physiological characteristics exhibited by the subject in these several regions, respectively. A display associated with the processor visually indicates these physiological characteristics.