Governor Deval Patrick today named Michael Pelgro, the first assistant Middlesex District attorney, to serve as acting district attorney until he appoints a replacement for Gerard T. Leone Jr., the district attorney who is resigning today for a job in a law firm.
The governor has not said how long Pelgro will serve as acting district attorney.
He has been a state and federal prosecutor for more than years 20 years. For 17 years, he was the assistant US attorney in Boston, in the Major Crimes Unit and the Organized Crime Drug Enforcement Task Force Unit.
He has also been an attorney in private firms, including five years in white-collar criminal defense and government investigations at Foley Hoag in Boston. A graduate of Boston College and Boston College Law School, he is married with four children.
Leone, a Democrat, is resigning to join Nixon Peabody, the firm that recently hired former Senator Scott Brown.
“I am very grateful that the governor has exhibited the confidence in me, to appoint me to such an important position of public trust,’’ Pelgro said in a statement.
Patrick has not said whom he will name to replace Leone. His choice would likely run for a full four-year term in the office next year.
The Globe has previously reported that legal insiders have mentioned a number of possible choices, including David Solet, chief of the Middlesex district attorney’s cyber-protection division, Chris Doherty, now a private attorney and the office’s former general counsel; Middlesex Clerk of Courts Michael Sullivan; and John Verner, criminal chief in the office of Attorney General Martha Coakley.
Middlesex County sheriff Peter Koutoujian is also a possible replacement for Leone. Rachel Kaprielian, registrar of motor vehicles and another Patrick appointee, has not ruled out interest in the seat.
Other lawmakers or former lawmakers warranting mention include state Senator Eileen Donoghue, Charles A. Murphy, former House Ways and Means chairman, and state Representative David Linsky, a former prosecutor.