Two police chiefs in Vermont’s largest city were ousted Monday after they anonymously taunted and “engaged” critics of Burlington’s police department, officials said.

Brandon Del Pozo. WPTZ

The first chief to go, Brandon del Pozo, resigned Monday. The departure came after a local newspaper, Seven Days, reported that the former chief had targeted Charles Winkleman, a local political activist and critic of the department, with a series of tweets over the summer under the handle “Winklewatchers.”

In a statement Friday, Burlington Mayor Miro Weinberger said del Pozo told him about the Twitter account on July 28. He also told Weinberger that he’d lied to a reporter when questioned about it.

“I immediately placed the chief on administrative leave, directed him to turn in his badge, gun, and city phone, and instructed him to cease using social media,” Weinberger said.

The mayor tasked city officials to further investigate, Weinberger said, and they learned that del Pozo had an “underlying mental health condition that impacted his actions.”

After a six week hiatus, del Pozo was cleared to return to work, Weinberger said.

Weinberger formally reprimanded del Pozo, he said, but declined further discipline, saying, among other things, that he had “self-reported” the tweets and that medical professionals had attributed them to his condition.

Three days after Seven Days' story, del Pozo — who apologized to the reporter he'd lied to — submitted his resignation letter to the mayor, Weinberger said. In a news conference announcing del Pozo's departure, the mayor appointed Deputy Chief Jan Wright as his temporary replacement.

But within hours, Weinberger had stripped Wright of that title after she disclosed operating an anonymous Facebook account under the pseudonym “Lori Spicer,” Weinberger said.

She made “comments about and engaged citizens in discussion of Police Department policy and practice,” Weinberger said.

A screenshot of a message obtained by NBC affiliate WBTS showed that she also appeared to have targeted Winkleman.

“Just admit it,” she reportedly wrote to him in a Facebook comment. “You are obsessed with Chief del Pozo. You can’t get enough of him. He definitely lives rent free in your head. Seek help.”

During a city council meeting after Wright’s demotion, Winkleman called for the resignation of Weinberger and Wright, WBTS reported. Referencing the Facebook message, he said: “Does that sound like a deputy that cares about mental health?”

Weinberger said that officials would now review all of Wright’s posts. He added that her disclosure hinted at a deeper problem within the department, and that he would enlist an outside investigator to examine its social media policies and activity.

The new acting chief, Jon Murad, “confirmed explicitly” to city officials that he had never used social media anonymously, Weinberger said in a statement.