The arrest came a day after a Columbia University graduate student first posted a video of Seldowitz telling the 24-year-old Egyptian-American man that he planned to use his government connections to have the halal food vendor's family arrested by Egypt's intelligence agency.
"The Mukhabarat in Egypt will get your parents," Seldowitz said, smirking. "Does your father like his fingernails? They'll take them out one by one."
Seldowitz called the man a "terrorist" in another video taken in a separate incident, and demanded to know his immigration status. He expressed disbelief when the vendor said he was an American citizen and was born in the United States. As the vendor asked him repeatedly to leave, Seldowitz also said that if the U.S. funded and supported Israel's killing of "4,000 Palestinian kids... it wasn't enough."
More than 14,500 people have been killed in Gaza by the U.S.-backed Israel Defense Forces since October 7, including more than 6,000 children.
On Wednesday evening, a video of Seldowitz being led out of a building by police was widely posted on social media.
Seldowitz has worked in the U.S. government under the Clinton, George W. Bush, and Obama administrations, serving as deputy director of the U.S. State Department's Office of Israel and Palestinian Affairs and as the acting director of the National Security Council South Asia Directorate.
The former U.S. official told WNBC in New York that his racist remarks about Muslim people and Arab Americans "were probably not appropriate," but defended his comments accusing the vendor of terrorism, claiming without evidence that the man had expressed support for Hamas.
After the videos of Seldowitz went viral on social media, New Yorkers rallied around the halal cart vendor, with some residents setting up a table and folding chairs outside the cart.
Mohamed Attia, managing director of the Street Vendor Project, which advocates for the rights of street vendors in New York, credited New York City Council member Julie Menin with helping to push for Seldowitz's arrest for harassing and stalking the man.
"Hate has no place in NYC," said Attia. "Much love to everybody who visited the vendors and expressed support."