A Compton camera system and method for detecting gamma radiation, comprising a gamma radiation source, at least one fast scintillator plate P1 of which the rise time to peak light is less than 1 ns, having a thickness greater than or equal to 5 mm, equipped with an array of segmented photodetectors (5) and a dedicated fast-reading microelectronic means. The system is characterised in that it is capable of measuring the spatial and temporal coordinates (X, Y, Z, T) and energy E at at least two successive positions of a gamma photon when said photon undergoes Compton scattering at a first point A before being absorbed at a second point B, by recognising circles of non-scattered photons corresponding to each scintillation interaction. The system has a module for estimating a valid Compton event. The detection system has two scintillator plates P1 and P2.