I have been awarded a judgment and can't collect. Can anyone give me some advice on what to do?

I've been frustrated for a couple of years now, trying my hardest to collect this money that is rightfully mine. I have tried serving subpoenas to several banks but can't find anything. This person must have his money stocked in his mattress or something. What else can I do? I live in New York and my judgment was awarded in New York.