Missable. This is another trophy/achievement that involves doing a specific thing during a story mission and since you can’t replay missions, then you will have one chance to do it. The mission in question is Black Project, where you must infiltrate a secret underground government base, but there’s a large above ground base to sneak around in to get to the former. In order to get this trophy/achievement, you will need to infiltrate the underground base without setting off the alarm above ground. As the game points out to you, there are spotlights and if you shoot more than two of them, then you will set off the alarm. Additionally, there are many guards around the compound, which complicates things a lot more.

The main objective when you first arrive at the compound is to get inside, of course, but the game points out some blast doors that are controlled by a switch on the one side of the compound. You should only bother with any spotlights that are in the way of the switch, but remember to not hit more than two. If you have the Silenced Pistol (can purchase it from Ammu-Nation), then use it to kill the guards in your way and avoid the others, if you can help it. Should an alarm get raised, then you will have to reset a recent save and try again. Once you make it into the underground base, you will get this. Note that the alarm will automatically go off while in the underground portion.