The gun used to kill two of three murder victims on the Upper West Side on Thursday is apparently missing. According to the NY Post, "Cops originally believed a semi-automatic pistol recovered at the Amsterdam Avenue slay scene was used by the gunman, Hector Quinones, but ballistics tests showed otherwise, NYPD spokesman Paul Browne said last night."

Now it's believed that Quinones may have "stashed the murder weapon -- thought to be the same type as the one recovered -- somewhere after Thursday's carnage or that the gun was picked up by someone." Quinones, who allegedly killed Carlos Rodriguez Sr., his son Carlos Jr., and his father-in-law Fernando Gonzales (shooting both Carlos Sr. and Carlos Jr.), fell to his death—tripping on his baggy pants— while trying to escape from the police, who had descended on the third floor apartment on the Upper West Side.

Rodriguez Sr. and Quinones apparently knew each other from stints in state prison; the gun found in the apartment was next to a lock box of heroin—over $100,000 worth of heroin was found.

Some business owners and residents weren't that surprised about the violence that broke out. One bar owner told the NY Times, "I’m not at all surprised. You’re looking at a stretch of Amsterdam that’s had a history of this type of behavior, and not all of it has moved out." The Times adds, "True enough. In the early 1970s, for example — before the advent of the chic boutique and the French toast brunch — the neighborhood was a notorious drug bazaar." And another store clerk said, "It wasn’t a big, big surprise to me because of having lived here for 30 years. It’s these new people coming in as gentrifiers saying, ‘Oh, God, really?’ This is life. It’s life. Things happen."