I've made up my mind :)
It's not entirely clear what the stool and rope have to do with it... But I think the old woman killed Arega (who else could have been spilling seeds?), and I think this old woman is Magnus; the phrase about the path clearly points to him.
The second murder – it's obviously the Mafia, but there are some issues with the evidence... I'm not quite sure if it's Lizard, Hermit, or Tieru... I don't want to risk using a townsfolk. And Magnus is the old woman; hang him, you won't be wrong :)

And another thought came to mind:
could Wesker have been the driver?
According to the description, no one has ever seen this person, and the glasses seem to hint at it... We need to think more about what this gives us.

Execute Magnus