Cephus Johnson, the uncle of Oscar Grant, has been appointed to the BART Police Citizen Review Board — the civilian oversight body that exists in large part because of his nephew's killing by a BART police officer on New Year's Day 2009. The BART Board of Directors unanimously selected Johnson on August 13 as the board's public-at-large representative, a seat appointed by the full board rather than by a single district director. A Seat Born From…