A method for correctly identifying at least one source, in particular at least one nuclide, enclosed in a human body and/or a container, is provided, the method comprising the following steps: detecting and measuring the at least one source by means of a gamma spectroscopic device; identifying, in a first estimation step, the at least one source by means of a standard nuclide identification procedure for evaluating a measured first spectrum of the at least one source; applying a second estimation step on the basis of the result of the first estimation step, wherein the result of the first estimation step is used for acquiring a plurality of second spectra of the at least one source found by the standard nuclide identification procedure for a plurality of absorption scenarios and for a plurality of scattering scenarios; and comparing the measured first spectrum with a scatter and absorber spectrum obtained from the plurality of second spectra generated in the second estimation step.