I heard about this case and was waiting for more details and here they are. Also as Anonymous in the last post said, do go to the SPCA website for more information.
While some people are suspecting abuse, my guess is that it's a hoarder. Why? There's the presence of two kinds of food bags - dog and cat food. Also the sheer number of cats is to me fishy. Yes it's possible that there is someone killing all these cats - but in most abuse cases we've seen, the bodies are thrown out. In this case, someone has taken quite a lot of trouble to conceal the deaths. We'll find out more and hopefully whomever it is will be stopped.