In this work we discuss the theoretical photo-double ionization spectrum of iodomethane which was obtained by the newly developed relativistic two-particle propagator and compare it to experimental data. For a correct interpretation of the spectral features in the outer valence region, spin–orbit effects play a major role and induce new features to the spectra. Additionally, wide-energy range single and double ionization spectra of iodomethane were calculated revealing possible electronic decay reactions after high-energy primary ionization. In the low energy region of the single ionization spectrum pronounced breakdown was observed resulting in a highly correlated manifold which was characterized in detail via population analysis.