Chief Explosives Scientist
Federal Bureau of Investigation
As the FBI’s premier bomb expert, leads U.S. and foreign law enforcement to determine how terrorist-made explosives work, and finds new ways to detect and stop them.
When there is a terrorist bombing, or a new type of explosive poses a threat to the U.S., the FBI primarily turns to one man: Kirk Yeager.
“Kirk is the FBI’s resident bomb expert,” said Christopher Doss, assistant director of the bureau’s Laboratory Division. “Anything that deals with explosives that comes to the FBI goes through Kirk.”
Indeed, Yeager has assisted with virtually every high-profile bombing of the past several years. After the terrorist bombings in March, he aided authorities in Brussels. In 2014, he led the effort to counter a bomb threat posed by Al Qaeda in the Arabian Peninsula. He was the FBI’s lead explosive scientist for the 2013 Boston Marathon bombing, the attempted 2010 Times Square bombing in New York and the 2009 case of the underwear bomber arrested in Detroit.
Yeager doesn’t just respond to crises. In his daily work, he oversees the bureau's research focused on getting a better understanding of the explosives terrorists use, according to Amy Hess, executive assistant director of the FBI’s Science and Technology Division. He also developed the FBI's advanced training material on terrorist explosives.
With such sought-after expertise, Yeager regularly confers with domestic and foreign law enforcement agencies, and has provided training to every bomb squad in the United States as well as to many foreign allies, Hess said.
“Kirk Yeager is instrumental to the FBI’s national security and counterterrorism efforts,” Hess said. “His research, teaching and technical contributions to the field of explosives have helped the FBI more effectively respond to threats in many major cases.”
As a chemist and an engineer, as well as one of the FBI’s five senior laboratory scientists, Yeager has been studying bomb-making for more than 20 years. His goal is to understand what ingredients are used, how bombs are made and how they can be detected. He seeks to use this knowledge to trace devices to specific terrorist organizations or known bomb-makers around the world.
In 2014, for example, working with colleagues at the FBI’s Terrorist Explosive Device Analytical Center and experts from other federal agencies, Yeager led the research on portable electronic devices widely used by terrorist organizations and considered a major threat. Yeager and his team built and tested these devices and found ways to upgrade existing explosive detection equipment. They then revised the training curriculum and improved aviation security.
That same year, Yeager and his interagency team quickly responded when Al Qaeda in the Arabian Peninsula published detailed instructions for making a bomb that could elude current detection methods.
The device was designed to target aircraft and could be made with match heads and ordinary kitchen materials. Yeager and the team built and tested the device, identified weaknesses in canine and instrument detection capabilities and researched ways to mitigate the threat. They also worked with the Transportation Security Administration to tighten screening procedures. And they accomplished all of this within 41 days of the published bomb recipe.
In 2013, Yeager reconstructed the Boston Marathon bomb to explain to the bureau’s senior leadership how it worked.
“Kirk is the go-to source, the brains behind understanding how you would put explosives together,” said Alice Isenberg, deputy assistant director of the FBI’s Laboratory Division.
The interagency collaboration on the Al Qaeda bomb, which included agencies within the Department of Homeland Security, validated and strengthened Yeager’s previous work to establish a cooperative agreement with DHS to build a new laboratory in Huntsville, Alabama, that will test bombs, detection equipment and new technologies.
Yeager’s work has saved the lives of countless U.S. civilians, law enforcement personnel and military troops, Isenberg said.
“Kirk is adept at thinking about explosives—how a bomb can be made or triggered—in unconventional ways,” Isenberg said. “His research has made air travel safer by enhancing safety and detection procedures for explosives.”
Described as an outstanding teacher and communicator, as well as a brilliant scientist, Yeager said he works to “bridge the gap between the lab and the operators in the field.”
As part of his work, he helped start a training program and developed information for bomb technicians across the country, including those employed by private companies. In one instance, the training materials helped a shipping company successfully stop a “lone wolf” plot, according to Yeager.
“Kirk has revolutionized training for the bomb tech community,” said the FBI’s Doss. “His ability to distill complex science into easily understood facts is unparalleled.”
Yeager said his biggest challenge is trying to keep up with the evolving nature of the terrorist threat. He will continue to “reproduce everything that the bad guys do,” he said, so he can save lives and “make a difference and contribute to the broader community.”