Mark Desire is still keeping the promise he made 24 years ago.
Desire, assistant director at the City of New York Office of Chief Medical Examiner, 55, has spent his entire career since September 11, 2001, working to identify victims of the terror attack and return their remains to families. “We made a promise that we would never give up,” he told The Post of himself and his team of scientists, technologists and anthropologists. “We promised those families that we would continue to advance the technology and never give up. That commitment is as great today as it was in 2001.”
The work happens three miles north of Ground Zero, inside a lab with sterilized air and so little humidity that breathing alone parches the throat. There, crew members who are often too young to remember the attack itself use cutting-edge methods to extract DNA from tiny bone fragments recovered from the World Trade Center site. They match these against a library of biological identifiers collected from victims’ personal items— toothbrushes, combs, and other belongings gathered in the days after the attack.
Desire describes the aftermath as “not only the largest forensic investigation in the United States but also the most difficult.” The obstacles are relentless: “jet fuel, fire, water used to put out the fire, chemicals in the building and sunlight all … all destroy DNA.”
Just last month, the 1,651st victim was identified. The person’s relatives requested anonymity and asked that the victim remain unnamed. Yet nearly 7,000 fragments that Desire and his group have analyzed still await matching.
“We’ve gone back to some bones 10 times, hoping that new technology will allow us to find DNA,” Desire explained. “If it’s a very small fragment that we’ve already tried [tech] on, and it now gives us just one chance, we need to ask ourselves if we should try now or wait for the technology to get better. That’s a big decision.”
The team has added forensic investigative genetic genealogy to its toolkit. This approach lets them tap into genetic banks, construct family trees, and track down previously unknown relatives of victims.
“Let’s say we have a DNA profile that does not match anything in the [DNA] databank — possibly, that’s because no relatives came forward,” Desire said. He noted that during the chaotic period after the attack, some family members believed they had given DNA samples when they actually had not. “We use commercial genealogy labs to help us [get started]. Then we take the forensics in-house so the NYPD genealogist can do analysis and an investigation. All these clues help us get closer and closer to solving.”
The work carries profound emotional weight. Desire recalled a mother pleading about her daughter who died in the Trade Center attack: “She said, ‘I don’t have much time, and I want to hold her once more before I die.'” He told her, “We work nonstop, every day, but I can’t predict who’s going to be next.” The mother responded, “I understand. But can you promise me this: After I die, and you do find her, can you pair her with me? I want her by my side.” He gave his word: “We’re not going to give up.”
Paul Keating experienced this dedication firsthand. In August 2025, the Floridian learned of a positive match for his mother Barbara, who had been aboard American Airlines flight 11, which crashed into the North Tower. “They went through the rubble centimeter by centimeter,” Keating told The Post, sounding amazed by it all. “For the first time in so many years she’s here. [The tragedy] never goes away. But any closure is good closure.”
When remains are delivered to loved ones, even in the smallest amounts, Desire witnesses the impact directly. “There is hugging and crying and the feeling is unbelievable. You can’t turn your back on that.”
On the morning of September 11, 2001, Desire was a criminalist in the Office of the Medical Examiner, using science to identify the missing and solve crimes. When the second plane hit, he and his colleagues raced downtown while both towers still stood. Their assignment was to preserve evidence and establish a temporary morgue, staying clear of first responders rushing into the buildings. When the South Tower collapsed, the force knocked Desire out of his shoes and shredded his Office of the Medical Examiner jacket. That garment and his wristwatch, which stopped at the moment of impact, now hang framed at the lab as inspiration to continue.
He returned to work on September 12. With fewer than 100 victim bodies fully intact, the mortuary examined fragmented remains. Desire was assigned to gathering DNA from reference samples supplied by relatives of the missing. An anthropologist helped the team distinguish human bones from animal remains— from restaurant supplies and packed lunches— and from 300-year-old bones buried beneath the Towers.
Sometimes belongings surface without their owners. “A firefighter’s helmet was recovered. His name was on it and his number. We generated a DNA profile [in case other remnants are found and prove to be a match],” Desire recalled. “We returned the helmet to his family, but we have not found that person yet.”
“I was here then, and am here now,” Desire said. “I feel honored to be doing this work. It’s a mission that has defined my career.”
The 25th anniversary commemoration ceremonies will take place at Ground Zero in Lower Manhattan on September 11.