The interim NYPD commissioner is a former FBI agent who investigated the 1993 World Trade Center bombing and later led the New York state Office of Homeland Security.Thomas Donlon will replace NYPD Commissioner Edward Caban, who resigned on Thursday amid a sprawling federal investigation into city officials. Mayor Eric Adams announced the appointment on Thursday.The appointment is a departure from the NYPD’s typical process of promoting from within. When Keechant Sewell stepped down as police commissioner last summer, Caban — the first deputy commissioner at the time — was appointed to the top seat.Donlon, a Bronx native, was never a street cop, according to his online biography. But he worked as chief of the FBI’s National Threat Center, and ran the FBI-NYPD Joint Terrorism Task Force, Adams said.“Tom joins a team at One Police Plaza that is relentlessly dedicated to public safety and protecting New Yorkers,” Adams said.A bio removed Thursday from a website for Global Security Resolutions, a company Donlon co-founded, described Donlon as a counterterrorism professional with expertise in crisis management investigations, executive protection, security and special events. He oversaw the FBI terrorism watch list and created the first terrorism threat database, according to the website. In addition to several roles involving terrorism and foreign counterintelligence, he worked in the violent crime section of the FBI’s safe street task forces.Global Security Resolutions produced an event series called “Focus Under Pressure” featuring Joe Pistone, the FBI agent who went undercover to investigate organized crime and was later portrayed in the movie “Donnie Brasco.”As a special agent with the Joint Terrorism Task Force in New York, Donlon investigated the 1993 World Trade Center bombing and was later cross-examined in court by one of the masterminds, Ramiz Yousef, who represented himself in court, according to news articles at the time. Yousef was convicted.Donlon also served as director of the state Office of Homeland Security during the administration of former New York Gov. David Paterson.Correction: An earlier version of this story misstated a position currently held by Thomas Donlon.