After a two-year probe into the city's mayoral security detail, the Department of Investigation (DOI) released a scathing 47-page report this month that determined a pattern of inappropriate security usage by Mayor Bill de Blasio and his family that it says amounts to a misuse of public resources for private benefit.

It's estimated that he cost the taxpayers hundreds of thousands of dollars, but the mayor has vigorously attacked the findings, calling them "inaccurate" and naive to the security threats he and his family members face on a daily basis. But questions about the report have continued to dog de Blasio, who has weathered a previous campaign finance scandal and is reportedly exploring a run for governor.

Read More: De Blasio Misused Public Resources During Failed Presidential Run, Report Finds

Here are the key takeaways of the report and why they matter.

What spurred the investigation?

The investigation began in August 2019 following allegations of security abuses reported by news outlets that focused on two issues: how the New York City Police Department provided vehicle escorts of his two children after they were no longer under 24/7 protection, and de Blasio's use of his security detail during his presidential campaign. DOI investigators relied on interviews with the mayor and his wife, First Lady Chirlane McCray, members of his security detail which are run under two units of the NYPD as well as cell phone records and text messages. They also reached out to federal agencies to determine their best practices for managing security for government officials and preventing abuse.

What were the most damaging findings?

During a four-month presidential campaign comprised of 21 trips totaling 60 days, investigators concluded that the NYPD paid approximately $319,794.20 for the mayor's security detail to accompany him. However, that estimate, the report says, only includes travel costs like flights, hotels, rental cars, fuel, and meals. It does not include the salary of the security detail members or any overtime they incurred.

To date, de Blasio has not reimbursed the city for those expenses. Instead, he has filed an appeal to the New York City Conflicts of Interest Board's ruling that said he should repay those costs.

The report goes into great depth on the use of security detail by de Blasio's two children, Dante and Chiara. It revisits the infamous 2019 incident in which the NYPD helped Chiara, 24 at the time, move from her Brooklyn apartment to Gracie Mansion. McCray told investigators that she was helping her daughter at the time and planned to use her own detail vehicle. But she said not all of the possessions, which included a futon, could fit. In one of several eyebrow-raising details, the report says that McCray said an NYPD van had “miraculously” arrived to assist. Meanwhile, a member of the mayor's security detail said he was instructed by his superior to drive the van to Chiara's apartment.

The mayor has always maintained that he knew nothing about the move, although cell phone records show a call placed from him to his wife during the move.

Dante, meanwhile, used the mayor's security detail to travel to and from Yale University, where he attended college, and to locations within the city, according to the report. Investigators found that following his graduation and beginning around December 2019 or January 2020, he was also driven by members of the NYPD to his job in Brooklyn. The practice stopped during the spring of 2020, around the time of the pandemic.

All told, the report cites 34 instances when Dante de Blasio rode in NYPD vehicles without the mayor or first lady present.

Is any of this illegal?

The report does not accuse the mayor of breaking any laws, but it does point out that the city's charter prohibits public servants from using city resources for personal advantage. It also cites rules adopted by the Conflicts of Interest Board, which does not allow for any use whatsoever of city time or resources for personal gain or political activities.

As a result, the mayor could face fines from the Conflicts of Interest Board for ethical violations.

There is, however, one potential criminal charge that could emerge—NYPD Inspector Howard Redmond, who is in charge of the mayor's security, has been referred to the Manhattan District Attorney’s Office for possible criminal prosecution. The report accuses Redman of obstructing the investigation by failing to respond to multiple requests to hand over to investigators his City Hall and NYPD-issued cell phones. DOI discovered not only deleted messages that they were able to track on the phones of other security detail members, but also an attempt by Redman to destroy his NYPD-issued phone.

The report further added that during his interview, Redman "demonstrated a lack of candor, repeatedly claimed he could not recall the facts around matters under his direct supervision, and gave multiple answers that were not credible in light of the objective evidence and the sworn statements of other witnesses."

How has the mayor responded?

"The entire report is riven with inaccuracies," de Blasio said last week on WNYC's Brian Lehrer Show. "There's not comprehensive research. They didn't talk to the people in charge."

He has defended his use of his security detail for himself and his family by saying that the policies were determined by the NYPD, not himself. He has also pointed to the increasingly dangerous nature of being a high-profile elected official. "We know that fraught reality of our politics has created a dynamic where there's much less safety and, in fact, families are also caught up in the reality, and the threats can come from anywhere at any time," he told reporters.

John Miller, the NYPD's Deputy Commissioner of counterterrorism who was not interviewed by the DOI, joined the mayor at the press conference and said that the department had logged a total of 308 separate threats involving the mayor, including 33 that referenced his family and 14 specifically against his children. In 2020, a police union, the Sergeants Benevolent Association, revealed Chiara's personal information on Twitter after she was one of hundreds of protesters arrested during the George Floyd protests.

With respect to his use of his security detail while he campaigned for president, de Blasio argued there is plenty of precedence in elected officials using their security detail without reimbursement. In his appeal letter to the Conflicts of Interest Board, he cited former Mayor Rudy Giuliani when he ran for U.S. Senate, as well as several governors who ran for president, including former New Jersey Governor Chris Christie.

Who is the DOI commissioner and what has she said?

Margaret Garnett has been DOI commissioner, a role that is considered the city's chief government watchdog, since December 2019. Prior to that, she worked as a deputy attorney general for the New York State Attorney General and spent 12 years as a federal prosecutor for the Southern District.

Garnett succeeded Mark Peters, who had led several damning investigations into city agencies, including the New York City Housing Authority's missed lead paint inspections. De Blasio controversially fired Peters, who later accused the mayor of trying to suppress his investigations.

During an interview on NY1, Garnett defended the integrity of her investigation into the mayor's use of his security detail and said the mayor had yet to specifically identify the alleged inaccuracies of the report. She spoke of "a pattern of conduct" in which public resources were available to the mayor's personal benefit.

Explaining that corrupt behavior can snowball, she added: "You reset a baseline of what is an unacceptable barrier between personal and official, and it just can lead to even worse things."

Garnett has argued that the "root problem" involving the mayor's security detail is the absence of any written policies or procedures. "Because it does not exist, neither the NYPD nor, as far as DOI is aware, any other City entity provided the Mayor, his family, or his representatives with any guidance — written or otherwise — concerning the appropriate or inappropriate uses of the security detail," the report states.

The report is likely to be Garnett's swan song. On Wednesday, it was announced that she will become the deputy attorney in the office of U.S. Attorney for the Southern District of New York Damian Williams. Her last day is November 10th.

Will there be any political fallout?

The mayor has continued to face questions this week about the report. But with less than three months left in office, there are a host of other pressing matters that have grabbed the spotlight: his decision to scrap the city's gifted and talented program, the ongoing Rikers crisis, and the city's ongoing vaccination efforts and the looming possibility of stricter mandates.

Still, de Blasio has made it clear that he intends to stay in public life so the investigation findings are likely to resurface, especially should he campaign for governor.

"Once a negative comes out, it's hard to overcome," said George Arzt, a political consultant who was a former press secretary for Mayor Ed Koch.

He said the report is especially damaging because ethical lapses have been a "cumulative issue" for de Blasio. Early on in his eight-year tenure, he was embroiled in multiple investigations involving his donors and whether they were granted special favors. Federal and state prosecutors ultimately did not find criminal wrongdoing, but the scandal will likely be remembered as part of the mayor's legacy.

Betsy Gotbaum, the executive director of Citizens Union, a good-government group, said New Yorkers should care about the DOI investigation because the conduct of abuse it details comes at their expense.

She said she found it astonishing that the mayor, a former public advocate, did not know that using his security detail while he was campaigning for another office was wrong. "If you’re campaigning, you have to reimburse," she said.

Like several others, including Democratic mayoral nominee, Eric Adams, she said she did not object to the children benefitting from the mayor's security detail. But she said she found the report's findings that the mayor's security was at times sent to pick up non-immediate family members like the mayor's brother galling. "This is so out there," she said.