This may come naturally in the normal progression of the game because it is often advantageous to perform brutal takedowns. So, you are often in circumstances where you may want to perform brutal takedowns in succession to keep other nearby enemies disoriented--a beneficial attribute of the brutal takedown. For the achievement to unlock three brutal takedowns must be performed one after the other. There can be a short interval between the brutal takedowns as long as it is not too long. However, the interval cannot be too long if the chain is to count. Moreover, all takedowns in the chain must be brutal takedowns.
Brutal Takedown: When a heavy melee attack is performed by holding
, a white sector in the circle surrounding the
prompt may appear. If the
button is released while the indicator is at that white sector, a brutal takedown will be performed. Controller vibration (if enabled) and a ‘ping’ sound effect may help the player with the timing on when to release the
button. If the B button is not released when the indicator is in the white sector then the ensuing takedown is a normal rather than a brutal takedown. Note, also, as mentioned above, that a heavy attack by holding
may not be able to be performed against alert, capable enemies unless they are first softened up with one or more light attacks performed by tapping the B button.
The below video shows a controlled, set-piece type environment where the three brutal takedowns can be performed to unlock the achievement. It is early in the game. Cassandra has become Lincoln's ally and the
Way of Flesh mission is underway. It is during the Prostitution Racket sub-mission. The location is just inside the First Baptist Church complex. Use the tac vest symbol that appears on the map to find it. The video explains the brutal takedown with the single enemy just inside the complex. Then, Lincoln goes around back to find several enemies and performs the brutal takedown on three of them in succession for the achievement.