We explicitly calculate Janossy densities for a special class of finite
determinantal point processes with several types of particles introduced by
Pr\"ahofer and Spohn and, in the full generality, by Johansson in connection
with the analysis of polynuclear growth models. The results of our paper
generalize the theorem we proved earlier with Borodin about the Janossy
densities in biorthogonal ensembles. In particular, our results can be applied
to coupled random matrices.Comment: We revised the introduction and added a couple of new reference