Execution on the White House Lawn
From Thomas Jefferson Encyclopedia
There is a very persistent story that Thomas Jefferson personally executed someone on the White House lawn for treason. This is not true. The story originated in the movie Swordfish (2001), where it is mentioned by John Travolta's character, Gabriel Shear.
Jefferson never personally killed anyone, nor were there any treason executions or convictions during his presidency. Jefferson did help write a "Bill to Attaint Josiah Philips and Others" in 1778, which ordered the trial and provided for the execution of the murderer and bandit Josiah Philips for treason. Josiah Philips was eventually found and convicted of robbery, not treason.