The D.C. firefighters assigned as the lead investigators in probes of the most significant blazes in the past year had little experience in arson cases and were not certified as fire investigators, sources told The Examiner.

In six major fires — including the Eastern Market fire, the town house fire that injured four fire fighters, and the five-alarm blaze at the Mount Pleasant apartment — the department used firefighters who had been detailed from rescue or engine companies to head up the probes.