New Jersey Gov. Phil Murphy (D) is expected to appoint his former chief of staff, George Helmy, to replace Sen. Bob Menendez (D-N.J.) for the remaining four and a half months of his term, according to a person with direct knowledge of the decision.

Menendez, a three-term senator, previously announced that he would resign from office effective Aug. 20, after being found guilty of 16 criminal counts of bribery, obstructing justice, acting as a foreign agent for Egypt, extortion and conspiring to commit those crimes.

Murphy is expected to call Helmy on Thursday with the offer to fill the vacancy, the person with knowledge of the decision said. The person spoke on the condition of anonymity to discuss deliberations that have not been publicly announced.

Helmy, 44, is a veteran of New Jersey politics. He served as an aide to Sen. Frank Lautenberg of New Jersey and later worked as a member of senior staff for Sen. Cory Booker (D-N.J.).

After serving as Murphy’s chief of staff for more than four years, Helmy left the New Jersey governor’s office last year to serve as executive vice president and chief external affairs and policy officer at RWJBarnabas Health, a large health-care system in the state.

He is also a commissioner of the Port Authority of New York and New Jersey. Helmy, who grew up in Jersey City, received his bachelor’s degree from Rutgers University and a master’s degree from Harvard University.

Upon Helmy’s exit from the governor’s office last year, Murphy praised his outgoing chief of staff as someone who had “put his heart and soul into serving the people of New Jersey.”

“I don’t know where we would be without George,” Murphy said at the time.

Rep. Andy Kim (D-N.J.), who won the Senate Democratic primary for Menendez’s seat, had indicated that he would accept the temporary appointment to the Senate if the governor asked. The governor’s wife, Tammy Murphy, who dropped out of the Senate race before primary votes were cast, took herself out of consideration for the temporary Senate appointment.

If appointed by Murphy as expected, Helmy will occupy the Senate seat until Menendez’s term ends in early January. Helmy will be succeeded by the person New Jerseyans elect this November to a full six-year term.

Kim, the Democratic Senate candidate in New Jersey, will face hotelier Curtis Bashaw, the Republican, for the full six-year term.