Siliconera reported on Christmas day that Final Fantasy publisher Square Enix had filed a trademark in Japan for something that appears to be called Murdered / Soul Suspect, Murdered: Soul Suspect, or possibly just Soul Suspect.
Practically nothing is known about the filing, though it doesn't appear to belong to any existing franchises. That means we could potentially have a new mystery property from Square Enix on our hands, possibly in the vein of Shu Takumi's Ghost Trick: Phantom Detective or even, as Siliconera speculates, Persona 4.
Square Enix has been responsible for some duds lately, though, so maybe don't get your hopes up too high just yet.
