  We propose a general and flexible capture-recapture model in continuous time.
Our model incorporates time-heterogeneity, observed and unobserved individual
heterogeneity, and behavioral response to capture. Behavioral response can
possibly have a delayed onset and a finite-time memory. Estimation of the
population size is based on the conditional likelihood after use of the EM
algorithm. We develop an application to the estimation of the number of adult
cannabinoid users in Italy.
