William Josefa Agbekoh, 24, was arrested Sunday and booked on charges of murder, assault and conspiracy, Buckelew said.
Lawon Marshawn Hall, 19, of Richmond, died after two men opened fire outside the Suede nightclub near Fisherman's Wharf, police said. Hall was shot several times; three other men were also hit and survived.
One of the suspected gunmen, 20-year-old Keandre Davis, also of Richmond, was arrested after being shot by a patrol special officer assigned to help provide security for the club.
Police have said both Davis and Hall were believed to be members of rival Richmond gangs.
Buckelew said Agbekoh is allegedly a friend of Davis.
Davis is charged with murder, assault with a semiautomatic firearm and negligent discharge of a firearm.
Prosecutors have not at this time filed gang charges against Davis, who remains at the hospital recovering from his wounds. His scheduled arraignment in San Francisco Superior Court today was postponed until Friday.
Suede has been the site of prior violence, according to city officials. Club owners have agreed to a 30-day closure.