The nation watched this month as the trial of Klansman Edgar Ray Killen forced the white citizens of Philadelphia, Miss., to come to terms with their history. But Killen's manslaughter conviction in the 1964 killing of three young civil rights workers should be a time for all Americans to confront our complicity in Southern-style segregation.

For generations too young to remember the actual events, the film "Mississippi Burning" recounted a version of the lynchings. Produced in 1988, the film is still widely shown on cable. But the filmmakers got the story only half right: The movie whitewashed the FBI. I know, because I dealt with the FBI during the hours leading up to the murders, when a simple intervention might have saved three lives.

As an 18-year-old volunteer at the Atlanta headquarters of the Student Nonviolent Coordinating Committee, I had been assigned to staff the telephone lines from Mississippi during the evening shift on June 21, 1964.

The movie accurately shows that Mississippi cops seized James Chaney, Mickey Schwerner and Andrew Goodman that afternoon, after they came to Neshoba County to investigate the burning of a black church. As the movie also recounts, Deputy Sheriff Cecil Price held them incommunicado at the county jail, then released them at 10 p.m. -- only to follow them to the county line, stop them again and hold them until his fellow Klansmen arrived to carry out their murderous scheme.

But the movie's portrayal of an FBI agent as a hero distorts the truth of this story. When the three activists failed to return to their Meridian, Miss., headquarters on schedule, we launched a well-established procedure. We had enough experience with both vigilante and police repression to know that their missed deadline was not a simple oversight and that the young men were probably in grave danger. I began calling area jails, hospitals and the Mississippi State Highway Patrol. When I spoke to the wife of the jailer in Philadelphia, she told me -- falsely, we later learned -- that Goodman, Chaney and Schwerner were not there.

My calls to FBI agents in their Meridian and Jackson offices brought a practiced mantra from that era: "The Bureau is not a law enforcement agency." If we could supply proof that a federal law had been broken, they told us, they would investigate.

Twice that evening I spoke with John Doar, head of the Justice Department's Civil Rights Division, at his Washington home. He assured me he would instruct the FBI to intervene. But J. Edgar Hoover's agents dashed those assurances and continued to stonewall as precious hours passed.

The FBI refused to participate until the following afternoon, when the station wagon of the three missing young men was found burned to a shell along a country road. The fears we had felt for their safety during the previous 24 frantic hours were all but confirmed.

Months later, when paid informants turned on their fellow Klansmen, the true story emerged. Had the FBI stopped by the jail on the afternoon of their arrest, the three civil rights workers would have been found alive. There was no place in that small lockup to hide the prisoners.

The FBI's stance in this sensational case was no aberration. Those of us working for civil rights organizations found the same lack of responsiveness each time we visited FBI offices to report Klan harassment, shootings or beatings -- even acts in progress.

But don't put all the blame on Hoover and his men. Remember that white America was largely indifferent while millions of African Americans lived under an apartheid-like system that condoned their disenfranchisement and oppression. Tens of thousands of restaurants, restrooms and entertainment facilities remained segregated, from Mississippi to Maryland. Few cried out against policies that denied black farmers federal cotton-growing allotments -- and sent their children to classes held in abandoned buses. Few paid attention when black people in the South who opposed these policies were routinely found dead, floating in rivers or lying along railroad tracks.

Today the worst publicly sanctioned forms of racism are behind us. A new generation of public officials has emerged to prosecute the most infamous bombings and lynchings, before all the murderers die at a peaceable old age that was denied their victims. But we do a disservice to those who stood up for justice when we distort facts to portray the FBI of the 1960s as part of the solution. If an FBI agent had rushed to the scene of the real crime, Schwerner, Chaney and Goodman could have been with us last summer to celebrate the 40th anniversary of the 1964 Civil Rights Act.

Sadly, it seems likely that without their sacrifice -- particularly without the deaths of young whites -- Americans might have chosen to wait even longer before outlawing segregation.

The writer is assistant director of the Teamsters union's port division in Washington.