A man who prosecutors say was one of several people who opened fire in a fatal mass shooting at a Brooklyn hookah lounge has been charged by federal authorities, officials said Wednesday. Elijah Roy, of Brooklyn, was charged with assault in aid of racketeering and a federal weapons charge, prosecutors from the Eastern District of New York said in a statement. The weapons charge applies when a person with a felony conviction is caught in possession of ammunition. Prosecutors say the Aug. 17 shooting, which killed three people and injured 11 others at a lounge in Crown Heights, was touched off by a dispute between members of rival Brooklyn street gangs. At about 3 a.m. on the night of the shooting, Roy and other alleged members of his gang began shooting at rivals, who returned fire, prosecutors said in a criminal complaint unsealed on Wednesday.