You may assume that some of them were lying low there and may be captured also! These bandits will fall under the same category as the other bandits outlined:

"For everyone else that signed up, you will still have the opportunity to capture the assailants even though they were not selected to thread the interrogation; you are free to make up your NPCs with the same basic guideline: they will not reveal their motive or their organization. You may turn them in to authorities (Wyver or Olympia or otherwise) or find creative ways to get rid of them."