Is there a process for identifying trolls on this site. I suspect that we may have one, but am unclear as to policies/procedures
I wouldn't be so quick to brand a user a troll. Everyone's allowed to have a bad day.
That said, if someone's being rude or otherwise disruptive, use your flags. The site's moderators have access to all the data they need to fairly assess a user's actions, and all the tools they need to restrict those actions if they deem it necessary.