The president of the Boulder Police Officers Association has filed a formal complaint against a member of the city’s Police Oversight Panel, accusing her of bias and undermining confidence in the city’s system for reviewing police misconduct complaints.
Bryan Plyter, president of the police union and an officer with the Boulder Police Department, filed the complaint in January 2026, alleging that Maria Soledad Diaz, co-chair of the city’s civilian Police Oversight Panel, violated the city’s code of conduct related to impartiality and the panel’s bylaws related to unbiased treatment.
“Her rhetoric is damaging and divisive,” the complaint reads. “It alludes to bias motivated policing practices which are not evident and her intent to represent only certain groups in the community which she believes are impacted by police misconduct.”
Diaz said she could not comment on an open investigation but called the complaint part of a broader pattern. “This code of conduct complaint comes to me in this succession of events in which the panel gets more and more destabilized,” she said.
The 11-member Police Oversight Panel reviews internal investigations into complaints of officer misconduct and makes recommendations to the police chief, who has the final say on disciplinary decisions. It was created in 2020 to provide independent civilian oversight after an officer pulled his gun on a Black student picking up trash outside his home. One of the city council’s stated goals in creating the panel was to ensure that “historically excluded communities have a voice in oversight.”
The complaint marks the first time the city’s police union has filed one against a panel member, according to a Boulder Reporting Lab review of code-of-conduct complaints. It cuts to a fundamental tension in the city’s police oversight program: The panel is expected both to review complaints against officers impartially and to give historically excluded communities a stronger role in oversight.
The union’s complaint argues that Diaz’s public statements about representing those communities show bias and raise questions about whether she can review cases fairly. It also cites recommendations Diaz made while conducting case reviews, including her decision to sustain discrimination allegations.
Victor King, a former panel member now serving on an advisory committee for seating new panel members, said the complaint takes Diaz’s statements out of context. He said it also conflates having an opinion about policing systems and policies with the case review process, which involves examining body camera footage, audio interviews and photographs.
“We’re making these fact-based assumptions, and we have our personal lived experience that also is going to flavor what we see in these videos, what we hear in the interviews,” King said. “That’s what makes it a good process. You have three different people doing this. She’s not alone. There are other people in the room who all have different perspectives, and that’s what makes the panel work.”
The complaint follows previous allegations of bias against a panel member. In 2023, the Boulder City Council voted to remove panel member Lisa Sweeney-Miran following complaints from residents who said she was biased against police. A federal lawsuit challenging that removal is pending, alleging violations of her constitutional rights to due process and protections against coercion and retaliation.
In the lead-up to the council’s 2023 vote to remove Sweeney-Miran, several police union members attended a city council meeting to urge the council to delay seating new panel members and to ensure that a subcommittee that nominated them followed city code. Some were on-duty and in uniform, according to police records, prompting a local political organizer to file a complaint alleging that seven officers violated department policy and city code by attending. Former Police Chief Maris Herold cleared all officers, according to a summary of the investigation.
The union’s complaint cites Diaz’s criticism of a recent change to how the oversight panel reviews misconduct cases. Under the city attorney’s interpretation of city code, the panel will no longer review cases in which both the police monitor and the Boulder Police Department clear officers of wrongdoing. Several panel members have said this change has compromised the panel’s mission.
Diaz has said the change limits the panel’s ability to weigh in on the types of discrimination allegations it was created to examine.
“I cannot in good conscience … advise any member of my community to file a complaint right now because I don’t have faith in the system,” Diaz said during a Police Oversight Panel meeting in November 2025. She said the voices of the Boulder Police Department and the police monitor do not represent those most impacted by police misconduct.
The police union’s complaint cites this statement and argues that such comments show a “clear biased approach” and go “against the idea of fairness, equity, and inclusivity.”
The complaint also cites an April 2025 misconduct case involving officers who responded to a medical call in which the complainant alleged officers used force and discriminated against her. Diaz was one of three panel members who reviewed the case.
According to police records, medical crews were treating a man in the back of an ambulance and told officers the woman was interfering with their treatment. Officers grabbed her, she attempted to hit them, and the officers told her she could be arrested. The woman spoke Spanish.
The panel exonerated the officers on use-of-force allegations but sustained bias allegations against two officers, finding their behavior was “culturally inappropriate” and “heavy-handed.” Panel members said one officer used informal pronouns when addressing the complainant in Spanish instead of more “respectful, professional language,” and called it “disrespectful” when officers asked the complainant’s daughter whether her mother had been drinking.
Police Chief Steve Redfearn ultimately determined the discrimination allegations were unfounded, siding with outside reviewers, the police department and the police monitor.
The union’s complaint states that the panel’s recommendation to sustain the discrimination allegations in this case carried “significant consequences for both the officers involved and the department” and prompted the city to hire an outside consultant to review the case, raising “serious concerns regarding the integrity of the panel’s review process.”
The City Attorney’s Office is reviewing the complaint.
Let the oversight panel do its job. There should be more transparency into how complaints are resolved, and this extra level of scrutiny into the details of police interactions with people is useful, especially when members of historically (and currently) marginalized communities are involved. Every city police department could benefit from an independent oversight panel if integrity and fairness is the goal, but I guess not if their morale is that easily damaged. The police should either admit they want the panel completely gone, or stop fighting against this transparency and accountability mechanism. From what I have read, the POP goes through an exhaustive process of reviewing all information in a case. This could be a learning opportunity for police to understand how to operate more appropriately and effectively. Instead, they felt it necessary to default to a defensive crouch and claim the panel goes “against the idea of fairness, equity, and inclusivity.”
How do they not comprehend how absurd and ironic that statement is in this context?
I completely agree. Her comment is so mild mannered and appropriate to the topic. A complaint like this is wildly overblown.
It’s fully expected that there should be conflict between the Police and their Oversight Committee. That’s expected – it’s the point of the structure.
Extremely disappointing in the behavior of the police here. But I guess I shouldn’t be surprised.
Officers are often put in extremely difficult positions involving irrational people. Plus Colorado made officers personally liable for any allegations against them. We are fortunate to have a single officer remain in staff.