Much more germane is the work he’s done on Wall Street, much of it in the mortgage arena.

According to regulatory records, Mr. Phillips has spent 38 years at an array of Wall Street firms, including Credit Suisse First Boston, Morgan Stanley and, most recently, BlackRock, the huge asset manager. While there, he headed the financial markets advisory and client solutions teams at BlackRock Solutions, the powerhouse advisory unit; he left in January.

Perhaps most salient on Mr. Phillips’s résumé are his years at Morgan Stanley, where he led the firm’s mortgage securities unit. He started in the company’s fixed income division in 1994 and rose to global head of securities products. He was also the chief executive of Morgan Stanley ABS Capital I Inc., signing mortgage securitization documents filed with the Securities and Exchange Commission.

As head of securities products, Mr. Phillips directed the unit of Morgan Stanley that packaged and sold billions of dollars of home loan bundles to Fannie Mae, Freddie Mac and other investors. Some of these securitizations blew up in the financial crisis, generating billions of dollars in losses to the investors who bought them.

Although he left the firm in May 2006, when the mortgage securitization machinery was starting to sputter, he is identified in lawsuits filed by investors who bought the toxic Morgan Stanley loan bundles. Two of those investors were Fannie and Freddie, the companies he is now charged with fixing.

In 2011, the Federal Housing Finance Agency, the overseer of Fannie and Freddie, sued Morgan Stanley on their behalf, naming Mr. Phillips as a defendant. The F.H.F.A. contended that Morgan Stanley had misled Fannie and Freddie about the quality of the loans it had pooled and sold to them. (A subsequent version of the lawsuit dropped Mr. Phillips from the defendants’ list but still cited him and his role at Morgan Stanley.)