Perfect sampling for posterior landmark distributions with an application to the detection of disease clusters Marc A. Loizeaux and Ian W. McKeague Abstract: We study perfect sampling for the posterior distribution in a class of spatial point process models introduced by Baddeley and van Lieshout (1993). For Neyman--Scott cluster models, perfect sampling from the posterior is shown to be computationally feasible via a coupling-from-the-past type algorithm of Kendall and Moller. An application to data on leukemia incidence in upstate New York is presented.