Amid mounting pressure to staff Mayor Zohran Mamdani's administration, top transition officials opted not to complete the full vetting process before announcing one of his earliest hires, a misstep that allowed an appointee’s antisemitic tweets to go undetected, sources tell Gothamist.
The decision to fast-track Catherine Almonte Da Costa as director of appointments, the details of which have not been previously reported, sheds new light on the challenges facing Mamdani as he takes over local government without a fat Rolodex or the longtime alliances typically associated with new mayors. Sources said Mamdani, a 34-year-old former state legislator with no prior experience in city government, was eager to show he was assembling a qualified and diverse team to carry out his ambitious agenda.
But the rush to roll out Mamdani's team resulted in Da Costa not finishing a critical internal step that likely would have uncovered her tweets from more than a decade ago, which included a reference to “money hungry Jews,” according to sources on the transition, who all requested anonymity because they were not authorized to discuss internal matters.
Da Costa had only completed an initial vetting that involved a search of public records that did not uncover her controversial social media posts because her handle was not easily identifiable.
“We had a rigorous process,” a source with knowledge of the vetting misstep told Gothamist. Da Costa “just wasn’t subjected to it.”
The person added: “It was rushed and sloppy.”
Da Costa’s hiring and resignation one day later created a cascade of problems for the nascent mayoral administration. The incident raised questions about how the transition was being managed. The Anti-Defamation League, which surfaced the tweets, called them indefensible. And Da Costa even had to be airbrushed out of a New York magazine cover photo showing the mayor with his senior leadership team.
Observers said Mayor Mamdani has moved into Gracie Mansion without a rolodex of experienced government hands, unlike many other mayors.
“I was not aware of these posts and I would not have hired her,” Mamdani told reporters afterward. He said there were “clear changes that need to be made” to the transition’s vetting process.
But a source with direct knowledge said key members of Mamdani’s inner circle signed off on the decision for the mayor to introduce Da Costa at a press conference without finishing her vetting. They included Dean Fuleihan, Mamdani’s first deputy mayor, and Elle Bisgaard-Church, Mamdani’s chief of staff. Elana Leopold, who served as the executive director of the transition, was also part of the discussions. Ali Najmi, another close adviser to Mamdani, was in charge of the vetting process.
Dora Pekec, a spokesperson for Mamdani, said that Da Costa’s vetting was no different than other hires. She said a review of Da Costa’s background before her introduction failed to include her X account.
“We have been clear that we changed our vetting process in December, after the ADL uncovered tweets our team had missed," Pekec said in a statement. “We’re extremely proud that in just 14 days, this administration has delivered universal child care for families, announced unprecedented protections for workers and consumers, and taken decisive action to protect tenants.”
Leopold, Najmi and Da Costa did not comment. The New York Times also reported on Da Costa's hiring.
Sources said they opted to move ahead without the full vetting in part because of Da Costa’s previous experience in city government and her relationship with the team. Da Costa, who was on leave from her job at a public relations firm, had already been helping the transition recruit and select candidates.
In addition to the internal vetting, new hires are required to complete a lengthy Department of Investigation background check. But it’s common for mayors to announce appointments before that process is completed.
Sources said that the transition felt under pressure as it faced questions about when Mamdani would begin announcing key hires like schools chancellor and transportation commissioner. Internally, members of the transition were tracking the timing of their announcements compared to de Blasio’s transition, the source with direct knowledge said. But the team had gotten off to a late start due to a competitive general election, unlike recent mayors.
Two days before Mamdani announced Da Costa’s hiring, Fuleihan was asked about the pace of hires at a public event hosted by the Citizen’s Budget Commission.
“This week, what are our odds? Are we going to get zero to three appointments or four and above?” said CBC President Andrew Rein, kicking off their conversation.
“You’re going to get appointments,” Fuleihan said. He noted his appointment was “faster than prior administrations.” He said they were looking to build a team that “can work well together and that reflects New York City,” calling it “a complicated task in a short period of time.”
Da Costa and Intergovernmental Affairs Director Jahmila Edwards were among Mamdani's first high-profile hires.
While directors of appointments are typically low-profile hires, Mamdani’s team seemed eager to highlight Da Costa, a 34-year-old Latina who was viewed in political circles as a smart veteran of city government.
In a statement announcing her resignation, Da Costa expressed her “deep regret” and said the posts from more than a decade ago were not “indicative of who I am.”
Fallout from Da Costa’s tweets has led to finger-pointing among Mamdani’s allies, sources said. Some senior members of Mamdani’s transition team have expressed frustration over how Da Costa’s appointment was handled, noting the team should have anticipated extra scrutiny given the skepticism around Mamdani from members of the business and Jewish communities. Days after Mamdani clinched the general election, the Anti-Defamation League announced that it would create a “Mamdani monitor” tracking his administration for any moves that could be construed as antisemitic.
Mamdani’s team tightened its vetting process after Da Costa’s resignation. The transition committee paid Tappan Research $25,000 to assist with its research process, according to the latest committee filing with the New York City Campaign Finance Board.
Sources within the transition have also raised questions about the administration’s overreliance on a close-knit circle of former aides to Mayor Bill de Blasio.
Mamdani has tapped an array of de Blasio alums. Melanie Hartzog, one of Mamdani’s Transition Committee co-chairs, served as a budget director and deputy mayor under de Blasio. Fuleihan, who was appointed just days after the transition launched, preceded Hartzog as budget director and later became first deputy mayor for de Blasio. Leopold and Da Costa had both served in the de Blasio administration and became friends.
Sal Albanese, a former city councilmember, cautioned that Mamdani, who was elected to be a disrupter, could fall prey to groupthink by hiring de Blasio alums.
“It’s an insider network,” said Albanese, who has informally advised Mamdani and his team.
“They’re already thinking about their next business venture,” he said. “I’ve seen it over and over again.”
Albanese, a Democrat, said he has privately urged Mamdani not to hire so many ex-de Blasio aides, who he said are “in the business of politics.” He said he raised the issue with Mamdani’s chief of staff Elle Bisgaard-Church during an August meeting about public safety.
At the same time, Albanese said he believed that Mamdani would learn from these kinds of mistakes. Many of Mamdani’s advisers, he said, don’t have the institutional knowledge or political instincts to run a government.
“They will develop it eventually,” he added.
