On Tuesday, just days after the 20th anniversary of the deadliest terrorist attack in U.S. history, forensic scientists who worked and are still working on identifying victims of the 9/11 attacks came together at ISHI 32 in a special panel titled, “From the Ashes- Lesson Learned from 9/11.”
The panel comprised Bruce Budowle, UNT Center for Human Identification; Mark Desire, New York City Office of Chief Medical Examiner; Alan Guisti, Federal Bureau of Investigation; and Timothy McMahon, Armed Forces DNA Identification Laboratory.
As the men discussed the role of their respective agencies in the forensic aftermath of the disaster, it almost felt like a “history of DNA” lesson. The limitations of DNA analysis in 2001 are far removed from 2021, which—at least partially—is due to the challenges highlighted by 9/11 victim identification.
For example, in 2001, the FBI laboratory was using 12 autosomal loci for human identification, had a single capillary electrophoresis instrument with no automation/robotics and was still using paper-based chain of custody and case files with no LIMS. Guisti, head of the DNA Casework Unit, says the team was still doing RFLP testing—which feels incredibly far removed from today’s SOPs.
For comparison’s sake, DNA analysis at the FBI lab in 2021 comprises the use of 21 autosomal loci, Y-STRs, real-time PCR quantitation, plate amplification, automation, 16 CE instruments, LIMS, digital case files and probabilistic genotyping.
Additionally, in 2001, CODIS was relatively new. The DNA database held just 750,929 convicted offender profiles at the time, compared with the 18.8 million and counting it holds today. Twenty years ago, there were zero profiles for missing persons/unidentified human remains, nor was there software capable of kinship analysis.
Now, CODIS has 2,169 missing person profiles, 28,391 profiles of relatives of the missing, 14,104 profiles of unidentified human remains and 16,612 pedigree trees.
“A lot of this capability came out of the 9/11 attacks when it became very obvious that CODIS was going to have to develop this capability to be as useful as it could be,” said Guisti, head of the DNA Casework Unit of the FBI lab, which was brought in at the time support NYC’s Office of the Chief Medical Examiner (OCME) and the Armed Forces DNA Identification Laboratory.
Moreover, the astounding DNA advancements made in the decade after the 9/11 attacks enabled the FBI lab to be prepared for yet another terrorist attack in 2013.
“A lot of these procedural advances and improvements happened in the early 2010s, and these helped us significantly with the Boston Marathon Bombing,” said Guisti, “especially working through a lot of evidence quickly.”
While the FBI lab received over 11,000 items and were able to obtain nuclear DNA from 300 (but make no identifications), Desire and the OCME made an ironclad commitment to type every recovered possible bone fragment—of which there was 100,000+.
Given the state of DNA technology in 2001, Desire and his team faced many of the same challenges Guisti did in the FBI lab. Regardless, today, 14,750 of the 21,905 remains transported to OCME have been identified—leaving 7,155.
Over the years, OCME took a phased approach to DNA analysis and human identification for the WTC attack. Phase 1, which commenced on Sept. 12, 2001, sought to generate DNA profiles with enough alleles to reach statistical threshold. This phase was 38% successful, meaning 38 of every 100 bone fragments yielded a useable profile. Phase 2 was a change in STR kits and a more robust grinding process, which yielded a 45% identification rate of previously negative samples. In Phase 3, mini-STRs and a new bone optimization protocol identified 54% of samples that were negative twice before.
The most recent Phase IV resulted in the identification of two new persons on Sept. 7, 2021—the first identifications since October 2019. Dorothy Morgan became the 1,646th identified person, and a man whose name is being withheld at the request of his family became the 1,647th identified person out of the 2,753 victims of 9/11.
Phase IV, which identified 59% of samples, included a new grinding protocol, demineralization and amplification technique. Now, the lab will process to Phase V—next-generation sequencing.
“Today, we work on what has failed four times,” said Desire. “There are samples waiting for NGS and we’re hoping that is what will push us over the threshold.”
Given the minuscule bone fragments they are working with, Desire said the analysts are always weighing the best option—should we test in this phase or wait until the next? While they never test to consume, Desire acknowledged that mass fatalities are a different breed, especially when the ultimate goal is an identification.
“We’ve released empty Eppendorf tubes to families with DNA extracts,” he said. “If there is nothing left from the sample, it’s about the identification.”
The importance of a plan
All four panelists agreed that the need for a disaster team and DNA disaster plan for future events is the largest lesson learned post-9/11.
In the days after the attack, Desire said he found a dusty, worthless disaster plan from 1995 that didn’t even include DNA.
“You should have a disaster team no matter what jurisdiction you are working in. You should have a plan, who to call, what your resources are, have it in writing, and know who your partners are. There were plenty of resources in the city, but we weren’t organized or ready. It’s very important to be organized and know who your support staff is outside your agency,” said Desire.
“You can’t just plan for X, you need to plan for X, Y and Z so you can scale as needed,” said McMahon, director of DoD DNA operations, Armed Forces Medical Examiner Systems. “If you don’t plan, how you are going to attack the situation on a scale-level?”
“It’s important to develop MOUs [memorandum of understanding] with others since you don’t know where the event could occur,” said Budowle, director of the UNT Center for Human Identification. “If we continue to innovate, share, exchange and work together, we can do great things.”
Photo: The lower perimeter columns of the north and west faces of Two World Trade Center (south tower) after the collapse of the building. Taken Nov. 11, 2001. Credit: FEMA photographer Bri Rodriguez