The city of Portland paid an outside law firm $6,098 to investigate a complaint that apparently led to the resignation of Rachel Talbot Ross, the city’s longtime director of equal opportunity and multicultural affairs.

The investigation by a lawyer at Perkins Thompson focused on an Aug. 26 incident that was likely captured on video and involved employees of Unified Parking Partners, a company that manages a number of private parking lots in the city, according to interviews and records that the Portland Press Herald obtained under the Freedom of Access Act.

Talbot Ross was placed on paid administrative leave a day after the incident. She submitted an undated letter of resignation after the investigation and signed a letter of separation with the city Oct. 7, according to records the newspaper obtained under a previous public records request. Her resignation, which ends a 21-year career at City Hall, is effective Dec. 11.

City records identify the two other individuals who figured in the investigation as Andy Martin and Shannon Farrell. Martin is a manager for Unified Parking Partners who previously worked for the city’s parking enforcement department. Farrell works for the city’s parking enforcement department and for Unified Parking as an enforcement attendant.

City officials have declined to comment on the matter, citing personnel issues. In response to a records request, the city released Talbot Ross’ undated resignation letter and the separation agreement she signed with City Manager Jon Jennings.

“As you know, we are conducting this investigation in response to a recent complaint relating to an incident that occurred on August 26, 2015,” Jennings wrote in a confidential Sept. 1 email to Talbot Ross that was released to the newspaper. He asked Talbot Ross to meet with Dawn Harmon, a lawyer at Perkins Thompson, for an interview lasting about two hours.

“We will keep this investigation as confidential as possible and will, as appropriate, inform you where we are in the process,” Jennings wrote, urging Talbot Ross to cooperate and “use your best judgment and discretion when discussing the investigation with others.”

Talbot Ross did not respond to a request for comment Wednesday. She confirmed her leave of absence in a brief interview Oct. 8, but declined to make any additional comment.

The latest documents from City Hall include an invoice showing the city paid Perkins Thompson $6,097.50 for 27 hours of work. The documents note that the firm submitted its report to the city on Sept. 15, but don’t include any description of what happened.

“We are needing an independent investigator to investigate an incident,” read an Aug. 28 email from the city to the firm.

Farrell, the parking attendant and city employee, declined to discuss the incident when contacted Tuesday night. She referred all questions to Unified Parking Partners owner Dan McNutt. McNutt declined to comment Wednesday.

Unified Parking, which has expanded quickly after opening in 2014, operates roughly 40 lots and garages, many of them privately owned and closed to the public during the day. The company has faced criticism on social media for its policy of “booting” cars in private lots if drivers overstay the pay-and-display tickets.

Such complaints have prompted city officials to consider adopting additional regulations that would affect the company. McNutt has told the Portland Press Herald that the criticism is unfair and the company keeps detailed records of when people arrive and depart, and videos its enforcement actions by having its employees wear body cameras similar to those used by police officers.

The records obtained by the newspaper don’t indicate whether the videos possessed by the city were taken from parking attendant body cameras. City officials have refused to release any videos involving Talbot Ross, saying they are personnel records that are not subject to disclosure under the Freedom of Access Act. City officials have refused requests for other records that might provide information about the leave, saying they contain confidential lawyer-client communications and personnel information.

Under state law, certain personnel records become public if a final disciplinary action is taken. Because Talbot Ross resigned and there was no disciplinary action, the material related to the investigation remains confidential.

As the city’s director of multicultural affairs, Talbot Ross reported to the city manager and had no staff. She served as a link between city government and immigrants, helping them deal with government bureaucracy. The position was scrutinized in 2010, when budget pressures led to an unsuccessful proposal to turn the $59,700-a-year full-time position into a part-time job. The position now pays $72,033 a year.

Talbot Ross is president of the Portland chapter of the NAACP, and her family has long ties to public service and the civil rights movement in Maine. Her father, former state Rep. Gerald Talbot of Portland, was Maine’s first black legislator. Her sister, Regina Phillips, is director of the city’s Refugee Services Program.

CORRECTION: This story was updated at 9:07 a.m. on Thursday, Oct. 22 to correct the name of Perkins Thompson lawyer Dawn Harmon.