According to officials, Chambers and Johnson, both of Philadelphia, were part of a group of five men who tried to gain entrance about 12:30 a.m. Sunday to a private party at the bowling alley. As one of them tried to force his way in, a fight broke out. Two of the uninvited guests pulled out handguns and fired into the party. Bullets struck a 21-year-old partygoer who fell onto one of the bowling lanes. One of the gunmen then stood over the victim and fired at him again, police said.