Serial Cleaner
29 Achievements
8-10h
BOOM! Headshot!
Get killed by a Shooter for the first time
20.8%
How to unlock the BOOM! Headshot! achievement in Serial Cleaner - Definitive Guide
Now the first place you can earn this is Contract 17: Mafia Manslaughter. You will notice there is a slaughter area in the top left of the restaurant full of pig carcasses, and there will be an enemy in grey up in this room. You can tell him apart because he is holding a gun in his hand.
Simply run into his field of vision and he will shoot you and you'll get your achievement. Be warned though, if he shoots you you'll (obviously) fail the contract and have to start over, so better to get this out of the way right at the start of the contract. Odds are you'll get this trying to complete the level naturally though.
This is all but impossible to not get when playing the game normally. In Contract 17 (Mafia Manslaughter), a new type of cop will appear wielding a pistol. If he sees you and you are within his line of sight, he will immediately shoot you and you will have to try the level again. It's more likely you will get this in Contract 18 (A shot in the dark) however, as there are far more Shooters here.
Once you reach Contract 17, you are introduced to the shooter police officer. These variants are wearing a light brown/grey uniform with a black hat. Once you are in their vision cone, they will shoot on sight and instant death.
There is one on Contract 17 near the top of the level, in the fridge near the rack of dead pigs. But it is easier to get this achievement on Contact 18 since there is an office patrolling near the spawn point.