To get the Blind Justice achievement in State of Decay 2 do the following:
Ferals are the special zombie class that runs on all fours and do so with intimidating speed and agility. Running over any of these special zombies with vehicles doesn't seem to unlock their corresponding achievements.
Bring a gun, maybe a shotgun if you have one, and it shouldn't be so hard to kill one even as it runs at you like a dog chasing a mail carrier. Careful of their pouncing ability.