Almost two years ago to the day, a team of officials from the Securities and Exchange Commission and the Federal Reserve Bank of New York quietly moved into the headquarters of Lehman Brothers. They were provided desks, phones, computers — and access to all of Lehman’s books and records. At any given moment, there were as many as a dozen government officials buzzing around Lehman’s offices.

These officials, whose work was kept under wraps at the time, were assigned by Timothy Geithner, then president of the New York Fed, and Christopher Cox, then the S.E.C. chairman, to monitor Lehman in light of the near collapse of Bear Stearns.

Similar teams from the S.E.C. and the Fed moved into the offices of Goldman Sachs, Morgan Stanley, Merrill Lynch and others.

There were plenty of reasons to send in these SWAT teams. With investors on edge about the veracity of valuations on Wall Street — and with hedge fund managers like David Einhorn publicly questioning Lehman’s numbers — the government examiners rifled through Lehman’s accounts. They also interviewed executives about various decisions, and previewed the quarterly earnings reports.