We have studied dissociative electron attachment (DEA) between low energy (≤0.6 eV) longitudinally polarized electrons and gas-phase chiral targets of 3-bromocamphor (C_{10}H_{15}BrO), 3-iodocamphor (C_{10}H_{15}IO), and 10-iodocamphor. The DEA rate depends on the sign of the incident electron helicity for a given target handedness, and it varies with both the atomic number (Z) and location of the heaviest atom in the molecule. While simple dynamic mechanisms can account for the asymmetry dependence on Z, they fail to explain the large asymmetry variation with the heavy atom location.