The shooter who ambushed and killed two upstate New York firefighters left a note behind indicating his intentions, police said today. "I still have to get ready to see how much of the neighborhood I can burn down and do what I like doing best -- killing people," the three-page typewritten note said. Two other firefighters who were wounded in the ambush are in stable condition after surgery, police say.  The gunman was convicted decades ago of killing his grandmother. He was found dead of a self-inflicted gunshot wound hours after the firefighters were shot.