Calling Card
I'm writing a significantly more mature book involving Pokémon in the real world. One of the major plotlines I'm working on right now involves a Ditto (shapeshifter) serial killer. Neo was abused by his owner, with the abuse culminating in her abandoning him in the woods. Through a series of events, Neo loses his mind and begins hunting and killing 14 women who resemble his owner. My protagonist, an FBI agent, is put on the case when the first body is discovered. Neo leaves behind a sort of psychic echo that resembles the sound a metronome makes. I've been trying to think of another calling card/pattern that he uses in his kills. I considered something to do with the eyes, but I don't want to go too heavy into gore. A person's eyes are vital in forming a bond with another, a bond that Neo lacked. I figured he'd be jealous, which is why he blinds the women post mortem, but it just doesn't feel correct for a reason I haven't been able to figure out. Do you guys have any ideas on a calling card or pattern that Neo might use or leave behind?