Buried in the Federal Bureau of Investigation file of deceased Black Panther leader Wopashitwe Mondo Even we Langa are secrets still hidden by Bureau censors, missing records, a misleading letter to a New Jersey Congressman, and a handwritten note revealing the FBI called off the search for a policeman's killer just four days after the officer was buried. An FBI memo dated Aug. 20, 1970, approves the Omaha Police request for help comparing voices - the voice of the person who called police with the voices of the suspects.