Body bombs: Threats and detection of suicide bombers

Following recent news of

an attempted attack on Mohammed Bin Nayef

, the head of Saudi Arabia's counter terrorism operations, this past August, many in the intelligence community have raised concerns about the ability to prevent such attacks. To learn more about improvised explosive devices (IEDs) worn on or even "in" the human body, interviewed Robert P. Daly, the chief technology officer for Brijot Imaging Systems, to discuss such threat vectors and technologies available to identify these threats. His interview appears below.

SIW: News that a terrorist managed to explode himself in an apparent attempt to kill a Saudi prince brought to light the use of "body bombs", where the explosive device is concealed inside the human body. Is there technology available to reliably detect threats hidden inside the body, such as in the intestines and abdomen?

Daly: Detection of concealed explosives in an abdomen or rectal areas would be done by the aid of a radiological investigation. There are commercially available semi-transmissive x-ray machines on the market. However, they are slow, difficult to use and require very specialized training. I am unaware of any security checkpoint deployments. Alternatively, the detonation device consisting of a cell phone, which was most likely concealed externally, could have easily been detected by imaging technologies using passive millimeter wave like the Brijot system, active millimeter wave or backscatter technologies. Additionally, the would-be assassin had given himself up during Ramadan and was given audience to the Prince for repentance, who although closely guarded, was not subjected to any screening other than metal detectors at the airports he passed through. Since the detonator and explosive material were made of plastic/non-metallic materials the metal detectors would not detect them externally or internally.

SIW: What are the types of detection technologies that can be applied in such situations?

Daly: Similar to the checkpoint screening you encounter at the airport, you would need to incorporate operating procedures as to where the subject divests themselves of anything in their pockets or concealed on their body. With the use of passive or active imaging technologies you would see anything not properly divested. If the person did not comply and detection was made, then they would be subject to secondary screening to resolve the alarm. In this case hidden items such things as cell phone (potential detonating device) could then be placed in an X-ray baggage to determine if dangerous. The subject in question has been detained and not given access to the restricted area, until cleared, so internally hidden explosives although not detected directly would be thwarted.

SIW: The device was believed to have been made from PETN, a type of plastic explosive. Traditional detection systems deployed at airports are only scanning for metallic objects. Are we seeing a major hole in aviation security? Can current technologies detect PETN? Can they detect very small devices such as the detonators now being used on IEDs?

Daly: There are tremendous capability gaps in aviation security as it is today. There are several commercial available imaging technologies, including Brijot's that can effectively detect explosives, liquids, gels, composites, plastics, narcotics, currency and other non-metallic contraband/threats. These systems can accurately detect such items as cell phones, used as detonators for IEDs.

SIW: Even after this terrorist incident, in which the attacker was said to have gone through airport security as part of the process to join the head of Saudi Arabia's counter terrorism operations Prince Mohammed Bin Nayef, we saw a statement issued this past week by the ACLU which disparages the use of "body scanning" technology. Despite such criticism, are you starting to see the tide of public opinion starting to change about today's new imaging technologies?

Most of the criticism is based on the privacy issues and safety concerns. The passive systems do not emit any energy or radiation of any kind. All active the imaging technologies have been determined safe by the standards set by the National Council of Radiation Protection & Measurement, but the perception of being unhealthy is still strong among the general public. With the privacy issues there is a definite advantage to using a passive system, like Brijot's, with it you do not have images that display any anatomical details, so the privacy issue is also a mute. There can be operational procedures in place to protect individual privacy but the images from active systems do reveal considerable anatomical details. It really all comes down to the big debate of security versus privacy, and unfortunately as more incidents occur; security, risk mitigation and deterrence become more and more important to everyone.