UPDATE - V1.3 - http://www.armaholic.com/forums.php?m=posts&id=141420
I have seen several threads (mainly in A3 forums) talking about silent takedowns for stealth missions and if BI will incorporate it... I thought it would be pretty simple to do so I had a crack at it. That is the story how this version of simple silent takedown script was born!
ZOD_STAKEDOWN V1
Allows close quarter silent kills - can be set up to have chance of failure.
1. Uses salute key as hotkey so you dont have to use the action menu (although that is still there if you want to use it that way!)
2. Basic setup in one line on any init field. Slightly more advanced setup (Chance of failure, specific units) through trigger and one line on act
3. Compatible with A2 and A3 with no editing
http://www.armaholic.com/page.php?id=19731
VERY difficult to do during the day. Much more feasible at night against an enemy without night vision!