If you're wondering why you can't land a critical hit when shooting Destiny: Rise of Iron's Splicer Vandals in the head, it's because you're a n00b who can't aim.
Just kidding. In all seriousness, you're not the only one having this issue.
Going by what users are reporting in the Destiny subreddit, the crit point has moved from the head to the throat.
According to user BIobertson, the mask worn by these fellas seems to nullify critical shots. In order to land a critical hit, players will need to hit them in a small space just under the helmet around under the chin.
BIobertson said the spot is "infuriatingly difficult to hit consistently," but if the player is using a handcannon it makes things a bit easier.
Another reddit user daftvalkyrie tested things out, and sure enough, it works. He reiterated how tricky the spot was to hit, especially since Dregs and Vandals look rather similar. Because of this, players will need to be "aware of what they're fighting."
So, if you are having a hard time landing crits with these particular enemies, now you know how it can be accomplished. Many thought the Splicer Vandal was bugged, but it just appears the spot needed to be hit to land the crit has moved.
Whether the crit spot being moved to the throat was intentional or not is unknown, but it sure sounds that way.
Destiny: Rise of Iron was released earlier this week on PS4 and Xbox One alongside Destiny: The Collection.