McCord was born in Waurika, Oklahoma and briefly attended Baylor University before receiving a B.B.A. from the University of Texas at Austin in 1949. In 1965, he received an M.S. in international affairs from George Washington University. McCord worked for the Central Intelligence Agency. In 1961, and under his direction, a counter-intelligence program was launched against the Fair Play for Cuba Committee. During his career McCord was a security coordinator for the Committee for the Re-Election of the President, and worked for the FBI and CIA, where he was in charge of physical security at Langley headquarters. He also held the rank of lieutenant colonel in the U.S. Air Force Reserve.
McCord was interviewed and then hired by Jack Caulfield in January 1972 "for strict, solely defensive security work at the Republican National Committee and the Committee to Re-Elect the President (CRP)". He and four other accomplices were arrested during the second break-in to the Democratic National Committee's headquarters at the Watergate complex on June 17, 1972. The arrests led to the Watergate scandal and resignation of President Nixon. McCord was one of the first men convicted in the Watergate criminal trial; on eight counts of conspiracy, burglary and wiretapping. In a later letter, written to U.S. District Judge John Sirica, McCord stated that his plea and testimony, some of which he claimed was perjured, were compelled by pressure from White House counsel John Dean and former Attorney General John N. Mitchell. The letter implicated senior individuals in the Richard Nixon administration of covering up the conspiracy that led to the burglary.
When Judge Sirica finished reading the letter, the courtroom exploded with excitement and reporters ran to the rear entrance to phone their newspapers. The bailiff kept banging for silence. It was a stunning development, exactly what I had been waiting for. Perjury at the trial. The involvement of others. It looked as if Watergate was about to break wide open.
McCord wrote a book about his connection with the Watergate burglary: