A 20-year-old Houstonian is set to appear in federal court on charges of aiding and abetting interference with commerce by robbery, announced U.S. Attorney Ryan K. Patrick. A federal grand jury returned the indictment against Xzavier Ivar Shephard Nov. 5. He is expected to make his initial appearance via video before U.S. Magistrate Judge Andrew M. Edison at 2 p.m. today. Originally charged by criminal complaint, Shephard was believed to be involved in at least four armed robberies of postal letter carriers since June.