_Slaugh_: Current clues
 
Suspect

▪ The murderer still has his/her jaw.
-------> Darth Malak

▪ The murderer doesn't wear a hat.
-------> Jack the Ripper; LeChuck

▪ The murderer doesn't wear glasses.
-------> Albert Wesker; Elexis Sinclaire

▪ The murderer is an adult.
-------> Abigail Williams; Alma Wade; Lucius Wagner

▪ The murderer doesn't wear an eyepatch.
-------> Dimitrij Volkov; Marquis Montalban; Sagat

▪ You won't find the murderer in Arkham City.
-------> Harley Quinn; Poison Ivy; The Joker

▪ Lara Croft has never met the murderer.
-------> Amanda Evert; Jacqueline Natla

▪ The murderer is not holding a gun.
-------> Agent 47; Big Jim Slade

Weapon

▪ The weapon doesn't require arrows.
-------> Bow

▪ The weapon doesn't need petrol to be effective.
-------> Chainsaw; Molotov Cocktail

▪ The weapon is not typically used to hit a ball.
-------> Baseball Bat; Golf Club

▪ The weapon doesn't use bullets or shells.
-------> Revolver; Shotgun

▪ The weapon doesn't have any electronic parts.
-------> Phaser; Time Bomb

▪ Other weapons have names starting with the same letter.
-------> Axe; Knife; Wine Bottle

▪ The weapon doesn't appear twice on the clue's picture.
-------> Candlestick; (Clawed Gloves?) Frying Pan

▪ The weapon has at least one metalic part.
-------> Poison; Rope
 
Location

▪ You can't access the restrooms from that location.
-------> Foyer

▪ No door leads to the water fountain.
-------> Parking

▪ You can't park a car here.
-------> Garage

▪ You don't need an umbrella when it's raining. ( Note: The front porch is covered )
-------> (Garden?) Swimming Pool

▪ It's not a hallway.
-------> Back Hall; Hall

▪ It's a room with at least one window.
-------> Cold Chamber; Front Porch; Garden; Laboratory; Tool House

▪ There is no locked door in this room.
-------> Kitchen; Dining Room

▪ It's a room with two or three windows.
-------> Ballroom; Lounge

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Thanks to: bler144.

ZFR: Hooray, Hitman exonerated :)
Jon Irenicus in Ballroom with Pickaxe