For example, when trying to silently take out (shoot) a guard on the top floor of the Shadow Raid job, some times (and seemingly at random), a guard on the roof will be alerted. This then leads to the failure of the heist.
My question is about the mechanics etc. for guards being alerted. Can guards be alerted by sound through a ceiling or wall? Are silenced pistols not silent enough and should I use melee attacks instead ? Or is it a game glitch and can I simply not kill guards when there is a guard on the roof too close?
Best Answer
Guards are alerted if they hear anything (running, gunshots, people being killed, etc) or see anything (body, drill, etc). The roof guards in Shadow Raid also have a very large line of sight, which also is greater on higher difficulties.
There are ways to reduce noise, and that is where there Ghost and / or Fugitive perks come in. If you get Shinobi or Hidden Blade aced then enemies make 95% less noise when killed, and this does make a good bit of difference. So if you want to reduce the chance of being caught get one of those perks. Also Winstone Wolf is good for the extra bodybag. :)
On a side note: the suppressor you add to your gun is just that, a suppressor, it doesn't block sound it just reduces it.