Okay, so this video (
http://youtube.com/watch?v=FGjMjFNhFrg)
[spoilers for the video game Dishonored, violent content] shows some kills with a melee weapon - the fencing sabre I believe?
So if you wanted to pull off these moves in GURPS, presumably according to Martial Arts guidelines, break down the manoeuvres and combat options used turn-by-turn.
I think one of the last ones involved a Reverse Grip thrust which left the sword in (Turn 1), followed by a torso grapple to the stunned target (Turn 2), followed by a quick contest to spin the target's facing (MA118, Turn 3), followed by an All-Out Attack (Double) to grapple the neck with both hands (Turn 4), followed by a Neck Snap to kill the target over another two or so turns (Turns 5-6?), and finish with a Ready to pull the sword back out.