I've re-examined the evidence on Lord Winter, and his writing style is... well, improper enough to fit the supposed profile of one of the murder writers, who may have had to pull from previous games in order to cover up his style.

Lord Winter is also a veteran, from the ancient era.

Spoiler Alert, click show to read: 
The ancient era, by the way, was that big long period of peace and quiet before Askthepizzaguy wandered into the gameroom.

As such, he meets the profile of someone who could fish out kill descriptions from previous mafia games (a strategy a newbie would not come up with, most likely) and someone who may have difficulty masking his writing.

I'll leave GSC alone for one round, and go for Lord Winter.

Unvote: Gaius Scribonius Curio
Vote: Lord Winter