I was struggling with this achievement for a while and couldn’t find any specific information on how to get it. Sharing my knowledge for those who need it.
Overview
Walkthrough
What I had equipped when obtaining the achievement:
Beanbag Shotgun
Revolver
Taser x 6
Flashbang x 5
Heavy Armor (Full) (Ceramic)
M320 Gas
Helmet Only
I italicised 3 of the above variables because we won’t be using or touching those items anyway. With information I got from my mates, they didn’t seem to affect the achievement as well.
I had the Taser equipped whenever I wasn’t switching to throw Flashbangs. When Bashing, I had the Taser out as well.
I strongly suggest you equip the AI with strong Lethal options such as the P90 as they will be doing most of the legwork.
Most importantly, you MUST hit suspects with the Taser, Flashbang and Bash (Melee) a minimum of THREE times each. So that’s 3 Taser stuns, 3 Flashbang stuns and 3 Bashes.
You DO NOT need to hit a different suspect each time. I literally just kept bashing surrendering suspects that I had already tased and got the achievement.