I live in NY, i have a petit larceny charge on my record now is there anyway to get this sealed?

I made an irrational move, I was robbed at gunpoint. I called the cops I even identified the guys who did it to me and the cops did NOTHING. My face was beaten in and there wasa bloody handprint on the door. I ran into one of the guys at a store and i beat him up and took his i pod. this is my first offense and as you can tell I was not thinking clearly. This is preventing me from getting a job at even WALMART! Is there anyway I can get this sealed? I live in NY so I know I cant get it expunged. What are the chances of getting a pardon? And please I know I made a stupid decision, I don't need anyone telling me how stupid it was.