Assassin/Day 1 - Trigger the silent alarm
From Create Your Own Story
You wait for a while, estimating the time it takes for the assassins to prepare and for the guards to get there. When the moment comes, you use your chance to get to a more heavily secured area of the place, triggering the alarm by doing so. After taking a quick look around the room, you realize it's a chemical laboratory and that it was a mistake to go there — it had better security for a reason.
There are even more interesting chemicals on the shelves of the wall cabinets, and while you could think of multiple ways to use them, you aren't sure if it's worth the risk anymore. This level of security most likely sent the alarm straight to the police, and you start expecting a SWAT team entering the building within a couple of minutes. The assassins most likely still takes a little longer — unless they want to surprise you with unusually short preparation, which has its obvious drawbacks.