"Never murder a man who is committing suicide"--Woodrow Wilson?

[Bapopik at AOL.COM]

MURDER A MAN WHO IS COMMITTING SUICIDE--456 Google hits
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I just ran into Safire's quotation of Woodrow Wilson, "Never murder a man
who is committing suicide." When I put some search terms in ProQuest, I get
seven William Safire columns!
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Did Wilson really say this, and what does Fred have? The earliest Safire
column is from 1972.