Federal and New York City authorities arrested 26-year-old Alexander Heifler of Hoboken, New Jersey, yesterday evening after foiling his plot to firebomb the home of prominent pro-Palestinian activist Nerdeen Kiswani.

An undercover New York Police Department detective identified Heifler online and infiltrated a group chat where he discussed the attack. The officer developed a relationship with Heifler, met him in person, and witnessed him assemble eight Molotov cocktails, destructive devices filled with flammable liquid, in his Hoboken apartment on Willow Avenue and Clinton Street on Thursday night. Authorities executed a search warrant, recovered the devices, and took Heifler into custody without incident.

Heifler had surveilled Kiswani's Brooklyn residence on March 4 and possessed her address. He told the undercover officer about plans to throw the Molotov cocktails at her home, hide out afterward, and flee the country. Discussions dated back to February, with Heifler mentioning the devices during a Feb. 10 video call.

The FBI's Joint Terrorism Task Force and the NYPD's Racially and Ethnically Motivated Extremism unit led the investigation. Late Thursday, they notified Kiswani, 31, and her legal team of the imminent threat. Heifler, affiliated with a pro-Israel group designated by the FBI as a terrorist organization, faces federal charges of unlawfully making and possessing destructive devices, which carry a maximum 20-year prison sentence.

He appeared before a magistrate judge in Newark federal court on Friday afternoon and was ordered held without bail. His public defender reserved the right to seek release later.

Kiswani, co-founder of the New York City-based group Within Our Lifetime, organizes pro-Palestinian protests, including those focused on the Gaza conflict and boycotts of Israel. She described the plot as "about to" occur in a social media post and vowed to continue her advocacy. "I feel very blessed that they were able to thwart this," she said, while attributing heightened threats to rhetoric from pro-Israel organizations and politicians.

NYPD Commissioner Jessica Tisch praised the undercover work. "This NYPD investigation uncovered an alleged plot. Our undercover officer identified and tracked the threat, first online and then in person, allowing us to disrupt the planned attack," she said. Officials, including Hoboken's mayor and the FBI, stated there is no ongoing threat to public safety.

The case highlights tensions amid pro-Palestinian activism in New York, where Kiswani has faced prior harassment and surveillance. Law enforcement emphasized the operation's success in preventing violence.