The low noise and high spatial resolution of charge-coupled devices (CCDs) and complementary metal-oxide-semiconductor (CMOS) active-pixel sensors have made them detectors of choice for digital imaging. Although the slow time response of these devices has limited their application in particle physics, for the case of rare-event searches, where the particle interaction rate is extremely low, their properties can be fully exploited to build detectors that outperform in many aspects the traditional technologies of the field. I will describe our efforts to characterize the response to radiation of the CCDs deployed in the DAMIC dark matter search. I will show how the exquisite spatial resolution of the detector allows for particle identification, and provides the unique capability to reject sequences of radioactive decay with utmost efficiency. I will present a recent study where we exploit these techniques to argue for the low-background potential of a large array of amorphous Se-82 imagers based on CMOS technology to search for neutrinoless double beta decay.