REVERE – Police continue to investigate a shooting that left a 24-year-old man dead in the foyer of a home on Bellingham Avenue Saturday night.Mario D. Rosa was found laying in a pool of his own blood near the front doorway of the three-floor building at around 10 p.m.Jake Wark of the Suffolk County District Attorney?s office said Rosa lived in the 170 Bellingham Ave. building, but police reports indicate that he was a resident of Everett.Nick Cipponeri, a resident of the building, said he was home studying when he heard three gunshots.?I didn?t hear an argument beforehand, just three bangs,” he said. “When I looked out my window, I didn?t see anyone with a gun, just three dark-skinned guys running. One looked like he was trying to hide behind a car, but then they all got into an SUV and drove away really fast.”The St. Louis, Mo., native said at first he was afraid to check out the scene, but when he heard police in the building he crept downstairs, peeked around the corner and saw a body in the foyer covered in blood.?I heard an EMT talking about brain matter and I was told to go back upstairs by the cops,” he said. “I could see that he was dead.”On Sunday, a cleaning crew was on hand to mop up the scene. A strong odor of bleach and a missing portion of carpet in the foyer were all that remained of the violent encounter.No arrests have been made.State police homicide detectives assigned to the Suffolk County DA?s office and Revere police are investigating the shooting. Anyone with information is urged to call Revere police at 781-286-8340 or State police at 617-727-8817.