One day after being hired by Mayor-elect Zohran Mamdani, Catherine Almonte Da Costa submitted her resignation after antisemitic statements in old Twitter posts dating back to 2011 surfaced Thursday. Mamdani transition sources tell NBC New York that he and his transition were unaware of the posts when they appointed Da Costa Wednesday. When Mamdani put Da Costa in charge of hiring for the city, she pledged to recruit diverse talent. “They have to reflect the rich diversity of race faith ethnicity that defines this City,” she said at the time. But today, 33-year-old Da Costa was apologizing for antisemitic posts dating back to when she was 18 years old. The posts were first found by the Anti-Defamation League, and then more problematic posts were uncovered by Timmy Facciola in a story on Substack. Soon after, Da Costa took down her Twitter account. In a statement released by the Mamdani transition team, Da Costa said she apologized and expressed “deep regret” for her past statements. “These statements are not indicative of who I am. As the mother of Jewish children, I feel a profound sense of sadness and remorse at the harm these words have caused,” said Da Costa. “As this has become a distraction from the work at hand, I have offered my resignation.” Mamdani subsequently issued his own statement, saying: “Catherine expressed her deep remorse over her past statements and tendered her resignation, and I accepted.” Some Jewish groups including the Anti-Defamation League are demanding an explanation from Mamdani. In other posts that surfaced Thursday, Da Costa apparently called police “piggies” and said that after President Donald Trump was elected to his first term in 2016, it was “ Da Costa had years of private sector experience shaping leadership strategies for corporations. A Dominican immigrant raised in Queens, she previously indicated she has already been helping Mamdani with hiring. She also previously held government jobs with the U.S. Census and in Mayor Bill de Blasio’s administration. EDITOR’S NOTE: This story has been updated to reflect that the Anti-Defamation League was the first to bring attention to Da Costa’s old posts, not Facciola, who later found more of her social media posts. When contacted by NBC New York, Facciola did not disclose that he learned about the posts from the ADL. ...read more read less