Usually, interactions like those we just had. We see who is most active on pushing players—Lanji in this case. And who defends them—me in this case.
You see if they have good reasons, if it looks like there's a contradiction between their current posts and previous posts, et cetera. For contradictions, it could be that Mafia strategy changed and they're communicating with one another to try something else.
But it's also important to keep notice of people on the sidelines.
@Don DaSlayer was here but didn't contribute much. It's curious.
Another hint is when you see a bunch of players suddenly voting for the same person, building a bandwagon to get them lynched.