Denver Auditor Tim O’Brien is frustrated with his dirty office windows.
Sitting down in the living room-like area of his office in the Wellington E. Webb Municipal Office Building, O’Brien says the view through the massive south-facing windows — a sweeping vantage of the Denver Art Museum, the Central Library and the rest of Civic Center — is excellent. But it’s hard to enjoy because the exterior windows are tinged with grime.
For O’Brien, who is in his third and final term, a clean view is paramount. Not just to see the city’s landscape — but also to get a clear sense of its budgets and work orders to determine if the city is using public dollars well. His office is charged with acting as a watchdog on the city’s strong-mayor system.
But after 10 years in that position, O’Brien says the role is getting tougher in some ways. He has butted heads with the mayor’s office more often, he said. Sometimes, city agencies make it difficult to get the information his team is seeking for audits. And he nearly lost $500,000 in his budget recently amid citywide financial woes, prompting public pushback by O’Brien against Mayor Mike Johnston’s proposed cut.
“I would say it’s really the result of a new administration,” he said, referring to his increasingly frequent run-ins with Johnston, who took office in mid-2023 and succeeded Michael Hancock. “We didn’t have some of these problems with the previous administration.”
The fight over the budget is one of the most public examples of the two disagreeing. O’Brien wrote a pointed letter in September to tell the mayor to “stop interfering” with his separately elected office. O’Brien has harshly criticized Johnston’s administration through its audits, digging in specifically on how the mayor’s homelessness program operates and tracks expenses.
He also audited the organizational culture of several key city agencies, including the mayor’s office and Denver Parks and Recreation, saying that staff members “did not understand the process for reporting concerns and did not feel comfortable doing so.”
A spokesman for Johnston says it isn’t surprising that the auditor and the mayor’s office sometimes disagree.
“Given the auditor’s role, it would, frankly, be pretty weird if we always saw eye to eye,” said Jon Ewing. “I can’t speak for the auditor’s relationship with the prior administration, which was to my memory often unsparing, but certainly feel like we’re making a good-faith effort to take his opinions and recommendations strongly into account.”
Johnston wasn’t available for an interview ahead of this story’s deadline, Ewing said.
From the budget fight to a recent debate among City Council members over who should investigate claims of unfair labor practices among city employees, O’Brien has found himself in the political spotlight on several occasions.
That’s somewhat unusual for a 40-plus-year certified public accountant who ran as an apolitical candidate in his first election in 2015. Unlike the auditors of the past few decades — including Dennis Gallagher, who served in the position from 2003 to 2015, and Don Mares, the auditor from 1995 to 2003 — O’Brien had never held an elected office before he became Denver’s auditor.
O’Brien served as the legislature-appointed state auditor from 1984 to 1995 and then worked as a consultant and as the CEO of the American Humane Association before running for office.
“I don’t give it (politics) a lot of thought,” he said. “I have a job to do. I have a code of conduct to adhere to.”
Councilman Kevin Flynn, who was a city hall reporter for the Rocky Mountain News for decades and has been on the council since 2015, said it was a notable change for Denver to elect an auditor who wasn’t overtly political.
“He brought a more professional outlook into the auditor’s office,” he said. “That’s kind of a welcome change.”
Flynn, who has also occasionally butted heads with the auditor over the years, added that he saw the tension between the mayor’s office and O’Brien as ordinary.
“It’s just the nature of the role,” Flynn said. “I don’t think this is unusual, I think it’s just current.”
Former Councilwoman Robin Kniech, who served on the council from 2011 to 2023, praised O’Brien’s work on labor issues but said other cities’ auditors do a better job of collaborating with the agencies they audit.
“The audits still seem more focused on an old-school gotcha that often awkwardly lags improvements that agencies (already have) underway,” she said.
Over the years, O’Brien has had conflicts with lots of people in the city, as when he sued the council over limits its members put in an ordinance giving him subpoena power and when he took on the Denver Zoo for refusing to open its books to his team. Since then, the office has secured fuller subpoena power — after winning the battle with the council — and expanded its work related to enforcing labor issues, including wage theft.
O’Brien made headlines earlier this year when he used that subpoena power to investigate wage theft complaints in the city’s strip clubs. He found that two of them, Diamond Cabaret and Rick’s Cabaret, “violated nearly every applicable provision” of Denver’s minimum-wage laws. His investigation resulted in a judge ordering those clubs to pay nearly $14 million in restitution and penalties to hundreds of workers.
The strip clubs’ owners accused O’Brien of “wielding subpoenas like weapons.”
Meticulous auditing process
Under Denver’s form of government, the mayor serves as the city’s chief executive, drafting the annual budget, setting the policy agenda and overseeing day-to-day operations. The 13 elected council members can propose legislation and make amendments to the budget. The mayor can veto their decisions, unless they override him with a supermajority.
The auditor — currently paid a salary set by ordinance at $178,152 — serves as a check over that system, primarily as a watchdog for the mayor’s office. Though he can’t force agencies to adopt his recommendations, the office issues them publicly, along with the audits’ findings.
Through discussions with the public, registered neighborhood organizations and city officials, the auditor’s office seeks input on which topics it should audit, O’Brien said. Then, the auditor’s staffers dig into the details to see if the programs are working as intended.
They look for things like inaccurate data reporting, inefficient spending and contract compliance. The office has about 100 staff members, about half of whom work in audit services. Beyond financial and performance audits, the office also reviews the city’s cybersecurity and IT services, something that could become more significant as Johnston leans into artificial intelligence programs.
“We are always looking at what risk the city faces in not achieving goals and objectives within given departments, given programs, given agencies,” O’Brien said.
Some of the office’s reports have sharply criticized the city’s delivery of services. One from 2024 found that the city wasn’t keeping homeless shelters safe or properly tracking spending on those services, which cost the city about $58 million per year. Another in 2023 showed that the Denver Police Department didn’t have plans to improve its staff retention.
In the spring, the office released an audit showing that the Office of Climate Action, Resiliency and Sustainability was using money from a voter-approved 0.25% sales tax hike — which was intended to help tackle climate change — for things beyond the allowable uses of the fund. That included at least one contractor’s meals, mileage and parking.
In 2026, the office plans to investigate Johnston’s All in Mile High homelessness program, the city’s budget process, the recently completed 16th Street mall reconstruction project and the city’s bikeway projects.
‘Running into difficulty’ getting info
The office is staffed by people from various backgrounds, from accounting professionals to public policy experts to lawyers. Once they decide on a topic for an audit, they request all sorts of planning documents, contracts, budgets and payroll records to begin their research.
Those are the type of documents that O’Brien says his office has struggled to obtain recently.
“On some audits, we’re running into difficulty getting access to information,” he said. “Much more than in the past.”
That happened as recently as September, when an auditor’s office review of the Office of the Independent Monitor’s civilian oversight of law enforcement “was chilled,” said auditor’s spokesman Michael Brannan. The office didn’t hand over a trove of internal communications the auditor requested, citing that they were protected under “deliberative process” exceptions to public record laws.
In the audit report, O’Brien’s staff wrote that they had been “significantly limited” in what they could review.
Completed audit reports include conclusions and recommendations to the agency investigated, leaving it up to the entity’s leaders to decide if they will accept or reject the suggestions. The auditor’s office tracks how many of its suggestions agencies accept and reject, and which they actually implement.
Since 2020, the office has made about 900 recommendations, according to a dashboard on the auditor’s website. The city has accepted about 94% of them, but it’s implemented only about 38%. More recently, since 2023, the city has accepted about 350 recommendations and implemented just 36, according to data provided by the auditor’s office. Another 140 recommendations are pending implementation.
Ewing said the mayor’s office “respects the auditor’s insight and guidance.”
“We take all of the office’s recommendations into deep consideration and respect the auditor’s role,” Ewing said.
As Denver faced budget shortfalls citywide earlier this year, triggering layoffs and service reductions, Johnston’s administration proposed cutting 3% of the auditor’s budget, which is set at about $16 million for 2026. O’Brien responded by saying he didn’t believe Johnston had the power to take that action. Ultimately, the council restored his full budget, and he vowed to curb his budget himself rather than leaving it up to the mayor.
“I do not believe he has that authority, and I’ve told him that half a dozen times at least,” he said of Johnston. “What’s to say he couldn’t cut it 30%? Or 100%?”
Work on labor draws attention
Besides the budget, recent attention has also focused on the office’s labor-related work.
When O’Brien was first elected, the auditor’s office enforced labor complaints only related to the prevailing wage — the city requirement that people working on publicly funded construction projects must receive certain wages depending on the type of work.
At that time, just four employees worked on labor issues, O’Brien said. That work has grown significantly under his administration. Now there are 40 employees dedicated to labor complaints.
Much of that work is investigations into wage theft — which occurs any time someone isn’t paid what they’re owed under law or as promised by their employer, including minimum wage violations, overtime violations and sick leave violations. In the year from November 2024 through October, the office said it returned about $2.3 million to workers.
Kniech, the former councilwoman, praised this work: “He has been a champion for workers and labor enforcement, helping to implement a new generation of protections passed by Council.”
O’Brien said he sees wage theft as a significant problem, estimating that workers could fall victim to more than $140 million in stolen wages every year in metro Denver.
After O’Brien filed his lawsuit against the council, it ultimately granted his office the ability to subpoena city agencies and businesses last year. So far, the office hasn’t used its subpoena power against city agencies. However, it has forced businesses to open their books at least a dozen times, Brannen said.
O’Brien says he doesn’t have any specific goals for the rest of his final term, which ends in July 2027. Several former auditors have gone on to run for mayor.
When asked whether he would do the same, O’Brien declined to comment. Until his term is finished, he hopes to continue improving transparency and accountability in Denver.
“Services could be better,” O’Brien said. “Services could be provided at significantly less expense. Data could be more secure.”
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