The Philadelphia District Attorney's office has issued an arrest warrant for Justin Smith, 23, in the shooting death of his pregnant girlfriend, Dianna Brice. PHILADELPHIA - The Federal Bureau of Investigation has joined the search for a man wanted in connection with the recent murder of his girlfriend and her unborn child in Philadelphia.Last week, the Philadelphia District Attorney's office issued a warrant for Smith, 23, in the murder of 21-year-old Dianna Brice.