• 1972 – Watergate scandal: An 18-1/2-minute gap appears in the tape recording of the conversations between U.S. President Richard Nixon and his advisers regarding the recent arrests of his operatives while breaking into the Watergate complex.

Nixon White House tapes

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Revelation of the taping system

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18½-minute gap
According to Nixon's secretary Rose Mary Woods, on September 29, 1973, she was reviewing a tape of the June 20, 1972, recordings, when she made "a terrible mistake" during transcription. While playing the tape on a Uher 5000, she answered a phone call. Reaching for the Uher 5000 stop button, she said that she mistakenly hit the button next to it, the record button. For the duration of the phone call, about five minutes, she kept her foot on the device's pedal, causing a five-minute portion of the tape to be rerecorded. When she listened to the tape, the gap had grown to 18-1/2 minutes. She later insisted that she was not responsible for the remaining 13 minutes of buzz.

The contents missing from the recording remain unknown, though the gap occurs during a conversation between Nixon and Haldeman three days after the Watergate break-in. Nixon claimed not to know the topics discussed during the gap. Haldeman's notes from the meeting show that among the topics of discussion were the arrests at the Watergate Hotel. White House lawyers first heard of the gap on the evening of November 14, 1973, and Judge Sirica, who had issued subpoenas for the tapes, was not told until November 21, after the president's attorneys had decided that there was "no innocent explanation" they could offer.


Rose Mary Woods attempting to demonstrate how she may have inadvertently created the gap


Uher 5000 with evidence tags

Woods was asked to demonstrate the position in which she was sitting when the accident occurred. Seated at a desk, she reached far back over her left shoulder for a telephone as her foot applied pressure to the pedal controlling the transcription machine. Her posture during the demonstration, dubbed the "Rose Mary Stretch", caused many political commentators to question the validity of the explanation.

In a grand jury interview in 1975, Nixon said that he initially believed that only four minutes of the tape were missing. He said that when he later heard that 18 minutes were missing, "I practically blew my stack."

In his 2014 book The Nixon Defense, Nixon's White House Counsel John Dean suggests that the full collection of recordings now available "largely answer the questions regarding what was known by the White House about the reasons for the break-in and bugging at the Democratic National Committee headquarters, as well as what was erased during the infamous 18 minute and 30 second gap during the June 20, 1972, conversation and why."

A variety of suggestions have been made as to who could have erased the tape. Years later, White House Chief of Staff Alexander Haig speculated that the erasures may conceivably have been caused by Nixon himself. According to Haig, the president was "spectacularly inept" at understanding and operating mechanical devices, and in the course of reviewing the tape in question, he may have caused the erasures by fumbling with the recorder's controls, though Haig could not say whether the erasures had occurred inadvertently or intentionally. In 1973, Haig had speculated aloud that the erasure was caused by an unidentified "sinister force." Others have suggested that Haig was involved in deliberately erasing the tapes with Nixon's involvement, or that the erasure was conducted by a White House lawyer.

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