The RD52 dual-readout calorimeter is a longitudinally unsegmented instrument intended for the detection of both electromagnetically and hadronically interacting particles with unprecedented precision. In this paper, the identification of the showering particles and, in particular, the identification of electrons and γs with this instrument are investigated. The techniques used for this purpose include differences in the shower development observed with scintillation light and Cherenkov radiation, the radial shower profile of the particles and the time structure (including the starting point) of the calorimeter signals. It turns out that, at 60GeV, electrons can be correctly identified in 99.8% of the cases, by means of criteria that eliminate 99.8% of the hadrons.