This has really been bugging me throughout the game. In previous games, when you were eligible to assassinate an enemy, it would show you that you need to press the Square button in order to do so. If two enemies were standing near each other, I never seemed to have any problem assassinating both of them at the same time. All you had to do was walk up behind two enemies and it would kill both of them.
However, it seems kind of random whether or not a double assassination occurs in Assassin's Creed III. It doesn't tell you when you're eligible to perform an assassination, and I can't seem to figure out why it's not letting me do double assassinations. Following the same patterns I've always utilized in previous games yields an unexpected result - only one of the enemies is killed, and the other starts attacking me. I've only been able to pull off one double assassination in my entire time playing the game so far (out of the around twenty I've attempted) and I have no idea what I did differently that time.
How do you perform a double assassination? Am I missing some major component of the game that I'm not realizing? Am I supposed to be aligning myself in some certain way?