From Dave Wilton:
Smoking Gun
This phrase, meaning incontrovertible evidence of guilt, is of relatively recent origin. It
actually was first coined by Republican congressman Barber Conable during the
Watergate investigation. The smoking gun in question then was a 23 June 1973 tape of a
conversation between Richard Nixon and his chief of staff, H.R. Haldeman:
Haldeman: ... the FBI is not under control ... and you think the thing to do is
to get them, the FBI, to stop?
Nixon: Right, fine.
Upon hearing the tape, Conable stated that it "looked like a smoking gun," meaning that
from the tape it was clear that Nixon had approved the cover up. Conable may not have
been the first to use the phrase, but he was the first to get credit for using it.
It is somewhat surprising that the phrase is so recent, given that its imagery is so vivid
and obvious. Arthur Conan Doyle, in The Gloria Scott, a Sherlock Holmes story published
in April 1893, used the phrase smoking pistol: "the chaplain stood with a smoking pistol
in his hand." Conan Doyle's usage, however, was quite literal and not figurative. Also, it
referred to a murder case while the current usage is usually found in a political context.
Finally, there is no evidence to indicate that the phrase was used in the intervening
seventy years.
