The FBI released more than 750 pages relating to the late U.S. Sen. Robert C. Byrd from its files in response to a Freedom of Information Act request from The Associated Press. The records date to the early 1950s, when the West Virginia Democrat was in the U.S. House. Byrd was serving a record 9th term in the U.S. Senate when he died in June 2010 at age 92. Among the revelations in the released records:

— Byrd's skepticism of civil rights figures extended to Martin Luther King Jr., but he condemned King's 1968 murder in a telegram to FBI Director J. Edgar Hoover. "I was not an admirer of Dr. King, but the assassination of anyone is a despicable act," Byrd wrote, while urging Hoover to investigate whether King was killed as part of a conspiracy.

— The released records include a previously unearthed FBI memo regarding Byrd and King, written just months before the April 1968 assassination. Byrd chaired the subcommittee that oversaw Washington, D.C., and objected to King's plans for massive civil disobedience protests in the capital that summer during a debate over home rule. "The Senator indicated it was time that King 'met his Waterloo' and that he felt this summer would do the trick," said the memo to Clyde Tolson, the FBI's second-in-command. "He stated this, of course, depended on whether or not the President would allow sufficient force to 'knock King down.'"

— The FBI investigated more than a dozen instances of threatening or harassing phone calls or letters directed at Byrd or his staff. Agents traced nearly all of these to people with mental health or substance abuse issues. One incident followed the April 1982 death of Byrd's grandson in a Virginia car accident.