It will be quite a while before we know many details about this man.
Judge John Lewis Smith, Jr. in 1977 ordered that all known copies of the recorded audiotapes and written transcripts resulting from the FBI's electronic surveillance of King between 1963 and 1968 to be held in the National Archives and sealed from public access until 2027. Source.
Im So Bored With MLK. An irreverent look at the Reverend. Language warning.