A European team of researchers led by the Swedish Defence Research Agency (FOI) is developing a mobile detection system that exposes sites where substances used in terrorist attacks are being produced. Researchers believe the system could ultimately be installed in police vehicles and used during regular patrols as a way of tracking bomb-making activities in urban areas. The device is an outcome of the LOTUS ('Localisation of threat substances in urban society') project, which was funded EUR 4.3 million under the Security Theme of the EU's Seventh Framework Programme (FP7) to create a system to detect illicit production of explosives and drugs.
By the time the project ends in 2011, the researchers will have a prototype in place that is capable of detecting high levels of threatening substances (bomb precursors) in an area. It would use GPS (global positioning system) technology to reveal information about the type of suspicious substance being emitted, the location, amount and time, all of which would then be sent through a wireless network to police authorities for further investigation.
The LOUTS researchers are currently testing the sensor that would be sensitive to hydrogen peroxide, the main bomb ingredient used in the London 7/7 bombings 5 years ago (it is alleged that the bombers bought 443 litres of hydrogen peroxide between April and July 2005 in either 1- or 4-litre containers).
The 7/7 bombings were a series of suicide attacks on London's public transport system that resulted in 52 fatalities (the 4 bombers also died). The approach the team has taken with the project is largely based on subsequent findings from the lead up to the attack on 7 July. So much so, that the kitchen in Leeds where the bombers made the lethal explosives has been replicated in the FOI lab.
The researchers believe that it is extremely difficult to prevent a terrorist attack when they are already in motion. FOI's Dr Henric Östmark explained that authorities tend to focus on finding bombs when they have already been made and placed for detonation. Although this can work very well at airport security points, it is simply impractical to scan high numbers of people at train stations during rush hour periods. Even if this were possible, a potential bomber caught in a station could potentially detonate a bomb at any point, rendering the scan useless.
But to prepare for an attack, such as 7/7, takes time, and for the LOTUS researchers the production stage is the right time for law enforcement to respond. 'It takes some time to make a bomb,' said Dr Östmark. 'We calculated that if you are going to make a bomb in a kitchen, it will take at least one month to do it.'
According to the team, the timeline for warning signs has several phases: (1) planning and financing; (2) obtaining equipment and materials; (3) preparation and production; transportation; and, finally, (4) execution of the attack. Surveillance to stop an attack must therefore take place during the first three phases; and this is where the LOTUS system is expected to help.
Since the project began in 2009, the focus for the researchers has been on testing three types of sensors: an 'ion mobility spectrometer' sensor (typically used for screenings at airports), and two based on 'differential mobility analysis' and infrared detection. The two essential elements are that the sensors be both fast and hypersensitive.
False alarms, say the researchers, are unlikely. The device’s central server will raise the alarm only when it detects high levels of specific chemicals over a substantial period of time. But what happens when a terrorist simply stops using hydrogen peroxide and switches to something new?
'We are looking at other potentials for making homemade explosives with homemade chemicals, ' Dr Östmark pointed out. 'We also ensure our sensors can be updated if the terrorist find some other way to make a bomb.'
When the prototype is ready, it will be tested in the Swedish capital city of Stockholm and another European city.