The review acknowledged that several informants were in Washington on Jan. 6, but said that only a handful were collecting information for the F.B.I. that day, contrary to conspiracy theories.More than two dozen F.B.I. informants were in Washington on Jan. 6, 2021, but, contrary to widespread conspiracy theories, bureau officials did not instruct them to encourage anyone to break the law as a pro-Trump mob stormed the Capitol that day, according to a report by a Justice Department watchdog released on Thursday.After a four-year investigation, the inspector general, Michael E. Horowitz, determined that F.B.I. leaders acted appropriately by dispatching some...