Arguably the piece of security tech with the greatest potential, commercial and in terms of utility, is trace detection. Mark Rowe queries however if specifiers will be able to make it fit human behaviour.
The December print edition of Professional Security Magazine offered what once would have been a scene out of a science-fiction story by Philip K Dick. It’s an airport terminal; someone is pushing a trolley with luggage. Nothing out of the ordinary; except that we know from the March 22, 2016 terrorist attack at Brussels Airport, that could be cover for a bomb. Vapour detection sensors – no more noticeable than a smoke alarm to the law-abiding public or the ‘hostile’ carrying out reconnaissance alike – pick up the bomb’s chemicals; the nearest and best-placed fixed video surveillance camera (or a drone?) is automatically directed to zoom in on the suspicious object and person. With facial recognition and AI, the suspect’s face is checked against a database. That can inform the police (the ‘human in the loop’ of all this tech) whether to approach the suspect, and in what force.
To the terrorist, in the jargon of counter-terrorism, a terminal (or a railway station) is ‘target-rich’ before the security controls that allow ticket-holders airside; passengers queueing to drop off baggage, people waiting in the arrivals hall. Better, then, for the search to happen on entry. Here lies the first of two problems that may scupper use of vapour detection. Because the promise of the market is colossal, considering all the places that well within our lifetimes have fitted metal detection arches. In the early 1990s as a newspaper reporter I attended shire magistrates courts, and a crown court. Not only was there no searching at the door, nor was there any suggestion there ought to be. Suicide terrorist acts, from 7-7 on in Britain, and knife-carrying, have prompted detection arches and search regimes before entry to courts, concert venues and sports stadiums. Railway stations, pubs and colleges may have regimes on occasion. The market could be on a par with fire and smoke detection – shopping centres too, any public building; trace detection could deter, offer reassurance.
The product would have to be highly accurate; an impressive sounding 99.8 per cent accuracy would not be at all good enough. Because consider its use at a railway terminus. Accuracy of 99.8 per cent means it’s accurate in all but two in a thousand cases. If a train arrives and 500 people get out at once, and walk to the exit, statistically it’s certain that one reading will be inaccurate. That might be someone with the suspicious trace is not picked up, or someone without a trace is flagged up as suspect (‘a false positive’). Ticket gates at main-line stations are already fraught enough, and fare-dodgers are tail-gating legitimate passengers by going through the gate straight after, and getting away with it, if only one or two rail staff are on duty at the line, busy with legit passengers with queries over electronic tickets that aren’t working (more less than 100pc accurate first time tech). this vapour detection scenario assumes one or two security officers at each terminus’ ticket gates. Quite apart from the security intervention happening at the crowded gate-line (which for the terrorist, would be ideal), are the cash-strapped railways ready to pay extra for such security?
Vapour detection, assuming it works perfectly, requires security architecture – some way to separate the suspect person from the flow of the law-abiding. This can work to the advantage of security, without the sophisticated detection. For some time, that I last saw earlier this month during the Crufts dog show, the NEC has an interesting set-up on the long corridor that takes you from Birmingham International station to the NEC halls (pictured is another entrance-exit, showing the digital signage advertising Servator, the ten-year-old police patrol method, cleverly showing dogs as part of the police ‘assets’).
Security officers are on duty at detection arches. There’s nothing to stop you from avoiding walking through an arch, by ignoring the queue tape and walking to the right, where those returning to the station can freely walk. Except that it’d be obvious you are avoiding the security measure. What follows is as much to plant doubt in the mind of the ‘hostile’ reading this as the security professional. For who’s to say what the detection arches are searching for (metal? the chemicals in explosives?) or how fine the setting of the device is? Heck, it might not even be plugged in, for all you know!? The security measure serves its purpose by being there, if it prompts someone with something to hide into behaving oddly, that the security officers can pick up. I’ve seen it years ago at Lichfield City rail station. Police set up impromptu such a detection arch, between the platform and exit. A handful of youths spotted it and made for the back of the crowd of evening commuters from Birmingham. The police (who’ve seen it all before) were at the back, to collar the suspects.
Here’s the second problem in the way of mass adoption of vapour detection. Lack of space. In British cities, it’s at a premium; ground is expensive, and old public buildings were not made with search regimes in mind. Hence sensitive sites such as the Central Criminal Court, the Old Bailey, has little stand-off room from the pavement (where it places temporary fencing to aid queueing on the street) before you enter and go through the search regime, ingeniously placed, that deposits you inside the court proper. At the National Gallery in Trafalgar Square, the queue for the search begins on the steps even at quiet times. There and in many places, at busy times, the queue has to snake outdoors, whatever the weather; not good for tourists. Again, perversely, that may create the very ‘crowded place’ (to use more counter-terrorism jargon) that terrorists seek. Beside, as seen tragically at the Brixton Academy in December 2022, a necessary search regime at a venue (whether to search for illegal drugs, or weapons) makes the entrance and pavement outside vulnerable to a crush, if simply too many people (including those without tickets, trying to enter regardless) occupy too little physical space. And again, a ‘crowded place’ attractive to a terrorist.
Perhaps some risk cannot be engineered out of urban living. Or, the bleak prospect is that if too many are carrying weapons in public places, too many for anyone to check, the readings from the product will be simply ignored, or used on an occasional ‘operation‘ rather than as everyday policing; like the ‘ping’ of automatic number plate recognition (ANPR), if far more vehicles are without insurance or otherwise suspect than there are cops on duty to stop them.
