As as mastermind, you can intimidate enemies.
BASIC: You can now intimidate non-special enemies. Less well trained enemies are easier to intimidate.
ACE: The power and range of your intimidation is increased.
In this video (bank heist 100% stealth), a player seems able to intimidate as many guards as he wants, the key point being to start yelling when the red excalamation point appears. But it's not possible to chain intimidations this way anymore (I tried it myself), as it's stated in one of the video's comments:
So it is possible to intimidate another enemy after a certain time ? How long ?