After a Department of Conservation and Recreation official was fired and another resigned, management changes are in the pipeline at the agency whose personnel has recently been at the center of a string of scandals, Gov. Charlie Baker said Wednesday.

Baker's office announced Wednesday that DCR personnel officer Jared Valanzola would be fired, following an internal investigation that showed he tried to coerce a staffer in the Executive Office of Environmental Affairs to dissuade her fiancé from running for office against Republican Sen. Don Humason of Westfield. EEA chief operating officer Michael Valanzola resigned in connection with the probe.

Five days ago, DCR commissioner Matthew Sisk resigned after a video surfaced showing him using the lights and sirens of his state vehicle in an alleged attempt to circumvent traffic. Sisk and DCR commissioner Leo Roy were both suspended for a week earlier in September for using state resources to plan and host a private party at a condo owned by Ron Kaufman, the state's Republican national committeeman.

Baker, speaking to reporters in the lobby of his office suite, said his administration would make additional announcements about the department "sometime in the next few days," involving "some folks who have many, many years at DCR moving into some senior positions" under Roy.

"While there are certainly some issues — which as I said on a number of times at a minimum disappointed me but frankly astonished me — and I believe we've acted quickly on those, I don't want to paint a brush that says everybody who works at DCR doesn't know what they're doing, because a lot of the people who are there do," the Swampscott Republican said. "I will say this: anybody who engages in any of the kinds of activity that have been associated with either this investigation or some of the stuff that's been reported on with respect to the misuse of state property and all the rest, we will deal with that and we will deal with it aggressively."

The investigation that led to Jared Valanzola's firing began in August after Cynthia Lewis, a program coordinator for the Massachusetts Environmental Police, alleged that her transfer from a Boston office to Fall River was a result of her fiancé's decision to run against Humason. Lewis is engaged to Southampton Democrat J.D. Parker-O'Grady, who is challenging Humason.

Humason was surprised and disappointed when he learned of the allegations, according to Baker, who said the senator called him once the news broke and said, "I have nothing to do with this, I want you to do the investigation."

The investigation found Lewis' transfer was not politically motivated, but that Valanzola "stated to Cynthia Lewis that her employment opportunity within EEA would be adversely affected by her [fiancé's] decision to run for political office," officials said.

While investigators found no conclusive evidence that Michael Valanzola — who is related to Jared Valanzola — sought retaliation against Lewis, the administration accepted his resignation and said it would not be possible for him "to remain in his role and execute his duties." Baker communications director Elizabeth Guyton said the move was "necessary to restore confidence in the human resources function for the secretariat."

A third employee, Energy and Environmental Affairs program manager Tim Sullivan, was issued a warning and will "undergo appropriate training" after Lewis said in a statement that he "invaded her personal space while speaking with her about the transfer," Guyton said.

Baker said he has "a lot of faith" in Energy and Environmental Affairs Secretary Matt Beaton, who oversees state environmental agencies, citing his work on energy legislation and an executive order focusing on climate change adaptation.

"Secretary Beaton was toe-to-toe with us all the way through this investigation," Baker said.

Lewis is on administrative leave at her request, according to Baker's office. The governor said he has not spoken with her directly but investigators did.

"She was anxious to see what the results of our investigation would be, and it's my hope that she'll be able to continue to serve in the executive branch," he said.

Gary Lambert, EEA's assistant secretary for operational services, will step into the role of acting chief operating officer, overseeing human resources functions after Michael Valanzola's resignation. Baker said Lambert "has a sterling 30-year record in state government."

"Gary's a pro and we're very happy that he's willing to do this through the end of the year to sort of straighten things out," Baker said.