PHOENIX — Nearly a year after the 2020 election, Arizona’s then-attorney general Mark Brnovich launched an investigation into voting in the state’s largest county that quickly consumed more than 10,000 hours of his staff’s time.

Former Arizona Attorney General Mark Brnovich, shown in 2020, left office last month. Bob Christie/Associated Press

Investigators prepared a report in March 2022 stating that virtually all claims of error and malfeasance were unfounded, according to internal documents reviewed by The Washington Post. Brnovich, a Republican, kept it private.

In April, the attorney general – who was running in the Republican Party primary for a U.S. Senate seat – released an “Interim Report” claiming that his office had discovered “serious vulnerabilities.” He left out edits from his own investigators refuting his assertions.

His office then compiled an “Election Review Summary” in September that systematically refuted accusations of widespread fraud and made clear that none of the complaining parties – from state lawmakers to self-styled “election integrity” groups – had presented any evidence to support their claims. Brnovich left office last month without releasing the summary.

That timeline emerges from documents released to The Post this week by Brnovich’s successor, Kris Mayes, a Democrat. She said she considered the taxpayer-funded investigation closed and, earlier this month, notified leaders on Maricopa County’s governing board that they were no longer in the state’s crosshairs.

The records show how Brnovich used his office to further claims about voting in Maricopa County that his own staff considered inaccurate. They suggest that his administration privately disregarded fact-checks provided by state investigators while publicly promoting incomplete accounts of the office’s work. The innuendo and inaccuracies, circulated not just in the far reaches of the internet but with the imprimatur of the state’s attorney general, helped make Arizona an epicenter of distrust in the democratic process, eroding confidence not just in the 2020 vote but in subsequent elections.

The documents – two investigative summaries and a draft letter with edits, totaling 41 pages – are far from an exhaustive record of Brnovich’s investigation. But they fill in details about the sometimes-enigmatic actions of the state’s former top law enforcement officer.

Brnovich did not respond to questions about his conduct of the probe, his decision not to release additional documents or differences between his public statements and his office’s private findings.

Brnovich quickly affirmed then-President Trump’s loss in Arizona in November 2020, angering fellow Republicans. And he went on to resist Trump’s efforts to overturn the vote. Yet he flirted with claims of fraud as he courted Republican support over the subsequent two years, trumpeting his interim report on a far-right radio show and saying, “It’s frustrating for all of us, because I think we all know what happened in 2020.” It was only in the final days before the November 2022 midterm election, several months after Brnovich had lost his Senate primary, that he began to denounce politicians who denied Trump’s defeat, calling them “clowns” engaged in a “giant grift.”

In releasing materials that Brnovich’s administration had kept from public view, Mayes said she was reorienting the work of the attorney general’s office – away from pursuing conspiratorial claims of fraud and toward protecting the right to vote, investigating the few cases of wrongdoing that typically occur every election and preventing threats against election workers.

“The people of Arizona had a right to know this information before the 2022 election,” Mayes said in an interview. “Maricopa County election officials had a right to know that they were cleared of wrongdoing. And every American had a right to know that the 2020 election in Arizona, which in part decided the presidency, was conducted accurately and fairly.”

The records released this week represent a fraction of the thousands of pages produced by investigators and attorneys during the investigation, including additional material from drafts of reports and interviews and correspondence with witnesses and election officials. Mayes’s staff is reviewing those documents and is redacting sensitive information before making them public in the coming months, said Richie Taylor, her spokesperson.

Brnovich’s administration did not release the investigative summaries, which The Post requested under Arizona’s public records law before he left office in January. Brnovich and his staff said repeatedly throughout the investigation that they were limited in what they could disclose since the probe was ongoing.

But his office did on occasion make public some aspects of its findings. On Aug. 1, the day before the state’s primary election, Brnovich said his office had finished its probe of allegations that hundreds of votes had been cast in the name of deceased people. His office found one instance. In December 2022, as Brnovich was preparing to leave office, an executive assistant wrote in an email to The Post that “regardless of transition, we will continue processing and will release when completed.”

The 2020 election in Maricopa County drew intense scrutiny because it’s the state’s largest voting jurisdiction, home to more than half of voters, and helped swing Arizona to Joe Biden and deliver him the presidency. Brnovich launched the investigation shortly after Cyber Ninjas, a Florida-based firm hired by the GOP-led state senate, ended its own review of the election in September 2021. The months-long legislative review, which was roundly criticized by election experts, affirmed Trump’s loss in the state. Brnovich was competing at the time in a Senate primary contest against Trump-aligned candidates who said they would have taken steps following the 2020 election to thwart certification of Biden’s victory.

The attorney general’s probe stretched through 2022, as Brnovich’s office spent more than 10,000 hours examining claims of irregularities, malfeasance and fraud, records show. At one point, the office set up a command center, and “the review of the audit was made a singular, high-level priority; all hands were assigned to work exclusively on reviewing the audit with other matters being placed on hold unless a matter required immediate action on our part,” a report said. Mayes said the office has about 60 investigators, all of whom participated in the probe at some point, along with lawyers and support staff.

By September 2022, a year into the inquiry, the special investigations section had received 638 election-related complaints and deemed 430 of them worthy of investigation. Of those, just 22 cases were submitted for prosecutorial review; two cases involving felons who illegally sought to vote were prosecuted, leading to convictions.

Brnovich never broadcast the full findings, declining to close the books on suspicions raised by an interim report with characterizations directly rebutted by his own office.

The interim report, delivered in the form of a letter to Karen Fann, then the Republican president of the state senate, was met by Trump allies as confirmation that voting in Maricopa County was corrupted. The letter, sent on April 6, highlighted management of early voting, saying, “We can report that there are problematic systemwide issues that relate to early ballot handling and verification.”

But Brnovich’s staff took issue with his criticism of the handling and verification of ballots, writing in a draft of the letter, “we did not uncover any criminality or fraud having been committed in this area during the 2020 general election.”

State investigators took issue with certain language included in an April 2022 draft of then-Arizona Attorney General Mark Brnovoch’s interim report on his office’s investigation of the 2020 election in Maricopa County, highlighting problematic text in yellow and offering corrections in blue. Arizona Attorney General

The staff comments were made in blue type, below disputed statements highlighted in yellow, and included in a document sent by a chief special agent in the criminal division to several others in the office on April 1. That document was forwarded to Brnovich’s top aide. The subject line was, “Additional Considerations for Draft Interim Report.” It’s not clear who else reviewed the document.

The considerations were largely not reflected in Brnovich’s final version.

Brnovich speculated that a large number of early ballots in the 2020 contest may have prevented county officials from properly verifying signatures on the ballots, even though his staff advised him that the county had rigorous training and processes, as well as additional staff, to ensure proper verification.

Brnovich went ahead with his claim that “Maricopa County had not always timely and fully responded to our requests for records,” even though staff advised in the draft document that it was the “collective opinion of . . . investigators” that the county “was cooperative and responsive to our requests.”

State investigators took issue with certain language included in an April 2022 draft of then-Arizona Attorney General Mark Brnovoch’s interim report on his office’s investigation of the 2020 election in Maricopa County, highlighting problematic text in yellow and offering corrections in blue. Arizona Attorney General

When Brnovich released his interim report, it was not accompanied by a fuller “Investigation Summary,” prepared by the assistant chief special agent and dated March 8. The 24-page summary described a range of allegations probed by the attorney general’s office, including improper signature verification, misuse of drop boxes and incomplete access to records for the state senate’s audit. That report was also shared with Brnovich’s top aide, Taylor said.

Virtually all allegations had been deemed unfounded, according to the summary. Several issues were listed as undetermined, including a claim by Cyber Ninjas that certain files had been deleted by the county; investigators had yet to review all archived data.

The summary revealed that there had been procedural violations in one instance – involving the retrieval of ballots from drop boxes. The state did not find that the county had mishandled ballots, according to the summary, but that it had not always properly recorded certain details, such as the time of retrieval.

Regarding signature verification, the issue highlighted in Brnovich’s interim report, the prepared summary found, “No improper Election Procedures were discovered during the Signature Verification review.”

Later the same year, Brnovich’s office came to further conclusions about the absence of any basis for claims of systematic fraud, but kept those findings private as well.

On Sept. 19, about a month after Brnovich had lost the GOP nomination for Senate to a MAGA-aligned candidate who insisted that “Trump won in 2020,” a memo summarized the work of investigators. The memo, drawn up by a chief special agent in anticipation of a final report, was not shared with office leadership since no such final report was ever drafted or requested, Taylor said.

The memo, titled “Election Review Summary,” emphasized that, “no evidence of election fraud, manipulation of the election process, or any instances of organized/coordinated fraud was provided by any of the complaining parties.”

A September 2022 memo summarizing the state probe of the 2020 election in Maricopa County went unreleased by the outgoing attorney general, Mark Brnovich. Arizona Attorney General

Of the more conspicuous claims examined by investigators – including those circulated by Cyber Ninjas, Texas-based True the Vote and others – the groups “did not provide any evidence to support their allegations,” the memo concluded. The information they did provide “was speculative in many instances and when investigated by our agents and support staff, was found to be inaccurate.”

The memo also reported that some high-profile Republican officials – who had publicly made fantastical claims of fraud – did not reiterate those assertions under questioning by agents, when they were subject to a state law prohibiting false reporting to law enforcement.

Mark Finchem, then a state representative who later ran unsuccessfully for secretary of state, had repeatedly claimed that a “source” told him that more than 30,000 fictitious votes had appeared during the general election in a county south of Phoenix. But when questioned by agents, he did not repeat the claim, “specifically stating he did not have any evidence of fraud and that he did not wish to take up our time.” Finchem provided four ballots that he said reflected a flawed voting process, but those ballots had not been counted and were unopened.

Sonny Borrelli, a Republican state senator who had alleged a coverup of election irregularities, did not repeat those claims during an interview but did provide what he said was the name of a deceased voter, the memo stated. Investigators learned that the alleged deceased voter was alive, had not voted and was not a resident of Arizona.

Investigators sought a meeting with Wendy Rogers, a Republican state senator and vocal election denier who now chairs the chamber’s elections committee. But Rogers refused to meet, the report said, “saying she was waiting to see the ‘perp walk’ of those who committed fraud during the election.”

No perp walk resulted from allegations presented to the unit, including that aerial objects flipped votes; that election workers scrubbed hard drives; and that satellites under the control of the Italian military penetrated vote-counting machines.