The longtime Mendota Heights police chief abruptly resigned from his post at Tuesday night’s City Council meeting, citing a need for change in the department that has endured a difficult year — preceded by a tumultuous decade.

Mike Aschenbrener, who has served as chief for 13 years, has overseen an embattled department that conducted three internal investigations of officers for various misconduct over the past 12 months.

Aschenbrener, 57, said the reason to act now was that a new mayor and two new council members will take office in January and they’re “interested in change.”

“I’m not confident … that they would trust what I had to say,” Aschenbrener said in a phone interview Thursday. “And that’s not a good place to come from.”

At the meeting, Mayor Sandra Krebsbach and all four council members said they were grateful for Aschenbrener’s service, but that it was time for new leadership to help rebuild the small town’s reputation.

“The city needs to move on,” said Krebsbach, who praised Aschenbrener for remaining professional during the most difficult times. “I want to thank you for always being here for the residents.”

They unanimously approved his resignation, but “with regrets,” said Council Member Ultan Duggan.

After some debate, the council voted to make recent hire Capt. Kelly McCarthy the next permanent chief. Aschenbrener’s retirement is effective Dec. 31, but he will serve his last day on Dec. 20.

Though he supports McCarthy, Aschenbrener said he was surprised she was given the job permanently rather than on an interim basis because he and City Administrator Mark McNeill had recommended letting the incoming council decide on a new chief.

In June, the council voted to fire Sgt. Bobby Lambert, a 20-year-veteran of the force who was put on paid administrative leave in February pending an internal-affairs investigation into the mishandling of evidence.

Lambert has claimed that the move to fire him was in retaliation for his 2012 demand that police investigate the apparent theft of a picnic table by another officer or officers. The city later spent $100,000 to examine the report.

That report links him with officer Scott Patrick, who months before being killed in the line of duty filed a whistleblower suit against the city and its police chief alleging retaliation for reporting two officers he said stole the table. His complaint, filed in 2014, accused Aschenbrener of retaliating against him for reporting the theft in 2008.

Mayor-Elect Neil Garlock, a former Mendota Heights sergeant who begins his two-year term in January, has been critical of the police department and ran his mayoral campaign largely on a call for new leadership.

Although Krebsbach called Aschenbrener a hard worker who fulfilled all his duties, she said she also would have encouraged him to step down next year if she’d won re-election. “It’s really time for this to end,” she said in a phone interview.

At least two council members defended Aschenbrener at the meeting, praising his performance and decorum during a challenging period that sparked a public backlash.

“I think Mike has done a spectacular job. I think he’s been beat up, abused and treated poorly by people in this town,” said Council Member Mike Povolny. “You’ve been accused of a lot of crap that you didn’t deserve.”

Council Member Steve Norton echoed those sentiments, emphasizing that if citizens knew information protected by data privacy laws, they likely would have a different opinion of Aschenbrener.

Incoming chief McCarthy was hired Nov. 1 from Lino Lakes, where she ran both the fire and police departments. “I don’t think we can do better,” Krebsbach said, saying that the city wanted to respond to citizens’ strong desire for stability in the department.