Trigger Detect Active Weapon?

So, according to the Wiki the left for dead 2 SDK Has it, but im making a Roleplay map and basically making a silent alarm system in the bank, i want it to detect if the player has an active gun. So how do i detect a active weapon? Thanks!

Unless the specific roleplay gamemode you are mapping for has a custom entity for this purpose, its impossible.

[editline]4th April 2016[/editline]

Also dont make a thread for every single small question. use the question megathread.

Could you make it detect 3 players then?