Why don't people believe the Government's conclusion that Mr. Ray was the lone killer? Part of the reason stems from the State of Tennessee's decision in 1969 to forgo a trial and accept Mr. Ray's plea bargain.

While a trial might not have disclosed the complete truth, it would have at least placed the state's evidence, and Mr. Ray's defense, into the historical record. In California, state officials rejected a similar plea offer from Sirhan Sirhan, Robert Kennedy's assassin. Instead, they forced him to stand trial and meticulously laid out the evidence.

Mr. Ray's guilty plea also thwarted early attempts to appoint a government board to investigate the murder. This absence of public scrutiny has prevented historians and serious investigators from thoroughly examining the case, because there is no accessible central body of documentation.

The F.B.I. has made tens of thousands of pages of its own files available. But many documents are heavily censored, and thousands of other files are still secret. Moreover, the largest repository of classified material was generated by the House Select Committee on Assassinations. From 1976 to 1978, the committee spent millions of dollars re-examining both Dr. King's death and the assassination of President John Kennedy. The committee's final report was helpful in explaining some of the complexities in the King case. Unfortunately, it followed the routine procedure of most Congressional bodies and sealed almost all its research, some 200 cubic feet of files, for 50 years. Such secrecy only added to the suspicions of those who questioned whether Mr. Ray was the lone assassin.

But there is a way to ease doubt. After the uproar that followed Oliver Stone's movie "J.F.K.," Congress passed the Assassination Materials Disclosure Act of 1992, which established the Assassination Records Review Board and gave it the authority to identify, secure and make available all records related to the Kennedy assassination. The board, appointed by President Clinton in 1994, determines which records are to be released immediately and which are to be kept back because of some concern for confidentiality or privacy.

Thanks to this law, thousands of documents have been released. While nothing has contradicted the original Warren Commission finding that Lee Harvey Oswald was the sole gunman, the files have filled in many details for historians and eliminated much of the suspicion that the Government was hiding something nefarious.

Why not pass a similar law and release the documents on the King assassination? The King family, instead of wasting its energies on an embarrassing campaign to free Mr. Ray, should pressure the Clinton Administration and Congress to do this. Some files -- like the F.B.I. surveillance of Dr. King's personal life -- could be legitimately withheld as too intrusive.