You can grab this trophy in the Service Bay after entering the Service Bay. There are multiple hooks to launch yourself off of and a plethora of enemies to assault.
After taking out the first enemy you encounter, scan the area so you can map out your plan of attack. Hop up onto one of the hooks, then press X to dismount right behind an enemy. Press O right before you land so you’ll do so silently. Activate Peeping Tom and then smack the crap out of the Splicer. Rinse and repeat twice more and the Trophy should pop.
If you have trouble or need to try again you restart at the checkpoint. Your counter won’t reset and you’ll have a fresh room of splicers to get the trophy.