High Quality Content by WIKIPEDIA articles! Linda Chatman Thomsen was the Director of the Division of Enforcement for the U.S. Securities and Exchange Commission from 2005 until early 2009. Since arriving at the SEC in 1995, she has worked under four SEC Chairmen: Arthur Levitt, Harvey Pitt, William H. Donaldson, and Christopher Cox. William Donaldson named her Director of the Division of Enforcement on May 12, 2005. Linda Thomsen is known for her role in the suits by the SEC against Enron and Martha Stewart, and for not having investigated Bernard Madoff. She succeeded Stephen M. Cutler.