Deathloop has 14 mostly naked character locations. One per map per time of day (excluding Karl's Bay Noon and Fristad Rock Evening which are inaccessible).
You must kill the character by shooting them for the Achivement / Trophy to unlock. No stabbing, kicking, or powers.
They can be done in any order.
Head out of entrance and go to the right. The guy is walking around the outside area near the RAK. Get him quick or he will have an accident and you'll miss him.
Head out and to the left. Go through the Candy Store. The guy is out the back looking at Charlie's Mansion.
Outside the library front in the crowd. Bodypainted, a little difficult to spot.
Outside the library front again, on top of some equipment.
Karl's Bay: Morning
In the alley between Dawn of Reason and Coital Center.
Karl's Bay: Afternoon
Hanger 1. Middle main floor.
Karl's Bay: Evening
Near same place as morning, but inside the AEON Coital Center.
Fristad Rock: Morning
On the dock where the security office is.
Fristad Rock: Noon
Bar below and to the right of Frank's Ramblin' Rock Club.
Fristad Rock: Afternoon
Bar below and to the right of Frank's Ramblin' Rock Club (again).
The Complex: Morning
In the main bunker vehicle area.
The Complex: Noon
Guy is walking around the Array Y area.
The Complex: Afternoon
Go to the other side of the map to the Complex's main entrance where a bunch of NPCs are. Bodypainted guy there.
The Complex: Evening
Head out of the right door quickly and shoot the guy on the floor.