Echoing every one else's guides to state where I got this achievement. Any place to get this is good to report, yeah?
When you finally escape Castle Dimitrescu and defeat Lady Dimitrescu's mutated form, you will escape out of a door and into a forked pathway. It has a save hut and a bridge you cannot cross. The one path has a locked door, which you need to shoot the padlock off, that continues the story. Break it and enter a cave path until you meet the Old Woman at an altar after a small swim. She will leave after a cutscene and the box on the table will have a key to leave the room. Once you are outside you will be in a place named
Ceremony Site. A gigantic metal dome will be on the ground directly in front of you and behind it will have 3 crows on the ground. Shoot a random shot to make them scatter, then pull out your shotgun and shoot the crow to your left (as the flight path is longer than the other two) as it takes flight. Reload your checkpoint and you will be in the same area as soon as you left the prior room. You don't even have to walk a single step. Rinse and repeat 5 times.
I'd like to give a helpful nod to using the reload tip from
alanp9 in their solution. It makes this achievement very easy.
If you had not killed any animal life prior to this you will also receive this achievement.