A day after investigators revealed they hadn't found the gun used in the grisly killings that rocked the Upper West Side last week, police recovered a bloody handgun near the Amsterdam Avenue crime scene. But the .380-caliber Beretta that police discovered was wedged between two trash bags in a garbage can about half a block from the place where the suspected gunman fell to his death from a fire escape, raising questions about how the firearm turned out in the garbage can and who put it there.

It's remains unclear if the newly found pistol was the weapon used in the slayings of Carlos Rodriguez Sr. and Carlos Rodriguez Jr. in their apartment. A similar gun was found inside the residence next to a lock box containing $100,000 of heroin, but ballistics tests revealed it wasn't the weapon used in the killings. The third victim, 87-year-old Fernando Gonzalez, was killed using a knife that was recovered at the scene.

Police suspect that Hector Quinones — who knew Carlos Sr. from a stint in prison — killed the three men in a dispute over drugs before falling to his death when he tripped on his baggy pants while fleeing police. Police believe that Quinones acted alone. "Our investigative premise is that the perp either hid the gun somewhere in the apartment before he fell from the fire escape, or he fell with the gun with him and that a bypasser or someone with access to the backyard stole the gun before the police arrived," NYPD spokesman Paul Browne told the Daily News.