We report a kinematically complete experiment on the production of CO{sup +} autoionizing states following photoionization of carbon monoxide below its vertical double ionization threshold. Momentum imaging spectroscopy is used to measure the energies and body-frame angular distributions of both photo- and autoionization electrons, as well as the kinetic energy release (KER) of the atomic ions. This data, in combination with ab initio theoretical calculations, provides insight into the nature of the cation states produced and their subsequent dissociation into autoionizing atomic (O*) fragments