Search the indicated location to get the corresponding weapon:
M19 Handgun: It is found in the first room on the right as you enter the attic (Guest House 2F). It is next to a box of bullets and a first aid med bottle.
Knife: It is given by the Deputy through the window (Main House 1F). You cannot miss it.
G17 Handgun: It is found in the garage (Main House 1F) during the first Jack Boss fight. Grab the Deputy’s lost gun off the ground during the battle.
M37 Shotgun: The shotgun is a powerful weapon that can be found in the Main Hall of the the building where you meet family Baker. First, get the Scorpion Key. It is found in the cellar with the slime monsters. The key is sticking out of a piece of meat. Next, use the Scorpion Key on the recreation room upstairs (go up the stairs from the Main Hall) to find the broken shotgun inside. Then, go back downstairs to the Main Hall (Main House 1F) and take the shotgun from the soldier statue’s hands and replace it with the broken shotgun to make the door behind you open so you can escape. You can also repair the broken shotgun. After escaping to the yard, look under the porch to find a removable metal part. Behind it is a box that contains a repair kit. Combine it with the broken shotgun to get a working shotgun.
Flamethrower: First, find the Burner Grip and Burner Nozzle in the Old House. The Burner Grip is found in a trash can on the deck outside the Gallery, near the bridge to the Save Room. The Burner Nozzle is found in the Water Station of the Old House. Combine both parts to create the flamethrower. This weapon is required to progress further into the Old House.
44 MAG: This powerful pistol is only available if you collect 9 Antique Coins and spend them in the Yard. The Trailer Save Room contains several bird cages with items inside. Use the Antique Coins to unlock the cage to get the 44 MAG.
Grenade Launcher: After getting the Crow Key, return to the Drawing Room on the first floor of the Main House to find the Grenade Launcher inside the supply closet.