Poop Vandalism

My building - Prospect Pl - corner of Rogers - was vandalized last night with poop spread on the front doors and in the keyholes.

I noticed from reading the Prospect Heights forum that this has happened to at least two buildings there. http://brooklynian.com/forum/prospect-heights/poop

Any advice on what we should do. We have just elected our board and the new officers are anxious to make sure something like this does not happen in the future.