People have a hard time voting for those who don't fight back.

Also mafians don't want to give up any info in their final moments. So, I think Plum maybe mafia, Klav's mention of Ema's persistance against Plum during her final days solidifies my susipicion. It could be a way to clear Ema, by getting a mafian who's got so much susipicion against her anyway, lynched. Or save Plum if she's the one killed.