  The Dark Matter Time Projection Chamber (DMTPC) collaboration is developing
low-pressure gas TPC detectors for measuring WIMP-nucleon interactions. Optical
readout with CCD cameras allows for the detection for the daily modulation in
the direction of the dark matter wind, while several charge readout channels
allow for the measurement of additional recoil properties. In this article, we
show that the addition of the charge readout analysis to the CCD allows us too
obtain a statistics-limited 90% C.L. upper limit on the $e^-$ rejection factor
of $5.6\times10^{-6}$ for recoils with energies between 40 and 200
keV$_{\mathrm{ee}}$. In addition, requiring coincidence between charge signals
and light in the CCD reduces CCD-specific backgrounds by more than two orders
of magnitude.
