  Latent class models have recently become popular for multiple-systems
estimation in human rights applications. However, it is currently unknown when
a given family of latent class models is identifiable in this context. We
provide necessary and sufficient conditions on the number of latent classes
needed for a family of latent class models to be identifiable. Along the way we
provide a mechanism for verifying identifiability in a class of
multiple-systems estimation models that allow for individual heterogeneity.
