Yes, he was appointed by George W Bush in 2001 to be the U S Attorney for the District of New Jersey. So he does have a history as a Prosecutor. He also prosecuted the planners of the 2007 Ft. Dix attack plot. He must be pretty good to have these prior credentials.
There you named the man who would make a superb Attorney General, if he wants the job. He may feel himself to be too old (age 71) but he was Associate AG under Reagan before returning to NYC and busting up the Five Families and becoming mayor.