What Is a Smoking Gun?

The term smoking gun refers to something that serves as evidence of a crime, such as fraud, or another illicit act. Put simply, a smoking gun is a piece of evidence that is strong enough to clearly prove something, whether that's to determine someone's guilt or to demonstrate the validity of a scientific theory. In most cases, a smoking gun is circumstantial rather than direct evidence.

Key Takeaways

  • A smoking gun serves as evidence of a crime, such as fraud, or another illicit act.
  • In most cases, a smoking gun is circumstantial rather than direct evidence.
  • The phrase's origins date back to "The Adventure of Gloria Scott," a short story written by Sir Arthur Conan Doyle.
  • The term has also migrated over to the field of science.

Understanding Smoking Gun

The origins of the phrase smoking gun seem to date back to the short story "The Adventure of Gloria Scott," which was written by Sir Arthur Conan Doyle. Published in 1893, the story featured Doyle's famous fictional detective Sherlock Holmes. In the story, Doyle states, "The chaplain stood with the smoking pistol in his hand." From that point, the phrase was used to conjure up the image of a killer holding a gun that was just fired as he stands over a dead body.

In most cases, the term smoking gun is commonly used to refer to criminal acts like financial fraud. As noted above, a smoking gun is normally used to describe circumstantial evidence. For instance, consider someone who just picks up a recently fired gun. They may not have actually fired it, but they are holding the smoking gun.

Although circumstantial, a smoking gun is often a piece of evidence that is irrefutable.

The phrase came into prominence in public conversation during the Watergate scandal of the 1970s. In June 1972, President Richard Nixon had a conversation in the White House with his aide H.R. Haldeman—a conversation that was taped. Nixon ordered Haldeman to get the FBI to stop investigating the Watergate break-in, coming up with various excuses to use for the order. When the existence and content of the audiotape came to light, it revealed that Nixon himself was in the cover-up and obstructed justice. The tape was widely referred to as the smoking gun tape. In fact, the House Judiciary Committee investigating was already asking "Where's the smoking gun?" in its efforts to link Nixon to the initial Watergate break-in and the subsequent cover-up.

There was a revival in the use of the term in 2003 when the search for weapons of mass destruction began. Some claimed they were being manufactured in Saddam Hussein's Iraq. Teams searching for indisputable evidence that these weapons existed were said to be looking for the smoking gun. Officials from the United Nations and reporters all used the term with this very specific meaning.

The term has also migrated over to the field of science. In 2014, the discovery of gravitational waves combined with a new theory regarding the rapid inflation of the universe at its beginnings was roundly cited as the smoking gun providing the validity of the Big Bang theory.

Example of Smoking Gun

Here is an example used in everyday language. On Feb. 6, 2002, CNN reported about the White House's unwillingness to provide the public with records relating to a number of meetings with the energy task force involving Enron, the Houston-based energy and utilities company that falsified its financial statements to hide losses from shareholders.

"Maybe there was no proof before, but there is now; a secret memo — personally handed to (Vice-President Dick) Cheney by Ken Lay (ex-Enron chairman and chief executive officer (CEO)), which helps explain why the White House is so skittish about Enron and why Cheney and (President George W.) Bush stubbornly refuse to release the records of those energy task force meetings. The memo was obtained by the San Francisco Chronicle and reported exclusively there last week. This is the Enron smoking gun."