"A relatively powerful handgun. It's in bad condition, but it still looks usable."
— Inventory description
In the demo, the M19 Handgun is located in the bathroom in the toilet and can only be picked up after flushing which can only be done by using the Valve Handle on the pipe first. Upon interacting with it, an animation plays where the character physically reaches to pick it up then racks it.
In the main game, the player finds it in the same house but it is placed in a different room. The player can find it on Guest House 3F in the room before the path leading to the attic.
Ethan Must Die
The M19 can be randomly found in 3-star purple boxes.