A Virginia city's first black, female police chief said she resigned "under duress" after some within the force resisted the reforms she tried to make.

Former Chief Tonya Chapman of the Portsmouth Police Department said during her three years at the department, she witnessed a "degree of bias and acts of systemic racism, discriminatory practices and abuse of authorities" that she'd never before encountered in her career.

She said some of the incidents she learned of were "so inflammatory" that she refused to discuss them publicly.

In a statement released Monday, Chapman said she believed members of a police union, whom she didn't name, were involved in her forced resignation.

The City of Portsmouth has so far declined to comment on Chapman's statement.

The first black woman to become police chief of a Virginia city said Monday she was forced to sign her own resignation letter "under duress" after encountering backlash from members of the force over her efforts to reform the department.

Former Chief Tonya Chapman of the Portsmouth Police Department said in a statement that despite her efforts to resolve "racial tensions" within the police department and repair relationships with the community, a "small contingency" of staff members resisted that change.

"I have never witnessed the degree of bias and acts of systemic racism, discriminatory practices, and abuse of authority in all of my almost 30 year career in law enforcement and public safety," Chapman said.

Chapman touted some successful reforms since she first arrived at the department in 2016, such as decreased homicide rates and an increased minority representation on the force. But she said the simmering racial tensions within the department became "blatantly apparent" that same year after an ex-officer was convicted for fatally shooting an unarmed black teenager.

Chapman said she was determined to change the culture within the department, but encountered incidents so egregious that she refused to detail them in her statement, saying only that she would share information with "the appropriate governmental entity."

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"I am acutely aware of the differences in the officers' attitudes and demeanor; therefore I was determined to change this culture," she said in her statement. "Some of these incidents are so inflammatory, I am reluctant to make this publically [sic] available out of concern for public safety."

Chapman also said she suspected a "highly influential fraternal organization" was involved in her forced resignation, though she didn't name the group.

"I can assure you that I did not 'quit' on the citizens of Portsmouth," she said in the statement. "My mother did not raise me to be a quitter. She raised me to be a strong woman. As such, my resignation was not tendered under my own volition. This was a forced resignation and our City Manager was the conduit."

A 'modern-day lynching'

Chapman said in her statement that she previously had a close relationship with the city manager, Lydia Pettis Patton, and viewed her as a "mentor and a mother figure." She said the pair even recently discussed future dinner plans.

But Chapman alleged that Patton abruptly requested a meeting one day while Chapman was out of town, refused to discuss what the meeting was for, and ignored Champan's phone calls.

She said when the pair eventually met, Patton read from a "scripted document" saying Chapman had lost the confidence of the police department and would need to either sign a pre-written resignation letter and receive two months' severance pay — or be fired.

"As with any organization, there were officers in the department that did not like my style of leadership and did not want me to hold them accountable for their actions," Chapman said in her statement. "Some quite frankly did not like taking direction from an African American female."

A spokeswoman for the City of Portsmouth did not immediately respond to INSIDER's request for comment, but told The New York Times in a statement that the issue was a "personnel matter" and the city would not be providing information.

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The NAACP blasted the city manager and Portsmouth Mayor John Rowe over Chapman's resignation, calling it a "modern-day lynching" and questioning exactly who in the police department purportedly had lost confidence in Chapman.

"Well whose confidence did she lose? Was it a collective vote? Or was it a privileged few?" Portsmouth NAACP President James Boyd told reporters in a press conference. He went on to demand answers directly from the mayor.

"You have a responsibility to this community, to outline why Chief Chapman was removed. It is not enough to hide behind the veil of staff or a city manager," Boyd said. "That is not leadership, that is cowardice."