The attorney who has been leading the state’s attempts to recoup pay from former New York Stock Exchange Chairman Richard A. Grasso will make his first court appearance today in a new role heading a special prosecution in another high-profile case, the 1988 killings of Arlene and Seymour Tankleff.

Benjamin E. Rosenberg, chief trial counsel for Attorney General Andrew M. Cuomo, will head a team of three attorneys in Mr. Cuomo’s office who will investigate the Tankleff murders. Governor Eliot Spitzer designated the attorney general as a special prosecutor in the case last weekend.