N.J. attorney general is appointed director of enforcement at the S.E.C.

Gary Gensler is turning to a longtime state and federal prosecutor to lead the enforcement division of the Securities and Exchange Commission.

Mr. Gensler, the S.E.C. chairman, announced on Tuesday that he had picked Gurbir Grewal, New Jersey’s attorney general since 2018, to run the all-important division at the nation’s top securities regulator. Mr. Grewal previously served as a federal prosecutor in Brooklyn and New Jersey, and was the chief prosecutor for Bergen County, one of New Jersey’s most populous counties.

As a government prosecutor, Mr. Grewal has overseen a number of high-profile securities fraud cases, including a 2015 case involving the hacking of thousands of company news releases so a gang of criminals could engage in insider trading.

Mr. Grewal “has the ideal combination of experience, values and leadership ability to helm the enforcement division at this critical time,” Mr. Gensler said in a statement.

Mr. Gensler’s first pick for the job, Alex Oh, a former Paul Weiss partner, had to resign just days after being named because of a controversy involving a federal judge’s ruling in a case for one of her corporate clients. Ms. Oh stepped down because the judge had taken issue with some of the conduct of Paul Weiss’s lawyers in defending its client, Exxon Mobil.

Some activists had criticized Ms. Oh’s selection because of her long history in private practice and representing large corporations. In picking Mr. Grewal, Mr. Gensler is likely to avoid similar criticism, given Mr. Grewal’s government tenure.

Mr. Grewal, 48, also has been in private practice, but has not worked for a private law firm in over a decade. As New Jersey attorney general, he oversees the state’s bureau of securities and runs a department with 750 lawyers, a few hundred fewer than the S.E.C.’s enforcement division.

He will take over his new job on July 26, replacing the acting enforcement director, Melissa Hodgman.