Momentum imaging measurements from two experiments are presented and interpreted with the aid of ab initio theoretical calculations to describe the dissociative electron attachment (DEA) dynamics of CO2. The dynamics of the transient negative ions of CO2- involve several conical intersections taking part in mechanisms that have only recently been understood. We address the problem of how the 4-eV 2Πu shape resonance in CO2 proceeds to dissociate to CO(1Σ+) + O-(2P) by DEA. © 2013 American Physical Society.