Congress, in 1979, concluded that MLK died as a result of a conspiracy. No one besides James Earl Ray was ever charged.
The USDOJ has a cold case initiative analyzing 100+ civil rights cold cases from the 60s. Martin Luther King, Jr.'s assassination is not among them. It should be added. And fingerprints, never matched to anyone, should be analyzed with the IAFIS database. That database has solved crimes older than King's. People have gone to jail for civil rights crimes as late as 2005. We need justice for MLK!