Previously published data on electron stimulated desorption (ESD) from condensed O2 or O2+ in matrices have been analyzed. Dissociative electron attachment (DEA) via the 2 Sigma sub g(+) resonant state can result in two different dissociation products (i.e. by proceeding to the dissociation limits O(3p) + O(-)(2-P) and O* (1D) + O(-)2(P). The O* (1D) product requires dissociation via a non-adiabatic curve crossing. O (1D) is the dominant DEA product in gaseous O2. Upon condensation, O(3P) becomes the dominant product; however, the branching ratio depends strongly on the kinetic energy of the dissociating atoms.