Britain's Web of Cameras Cracks Poisoning Case

choi

Ellen Barry, Britain's Web of Cameras Poisoning Case; Landmark test leads to charges in attack on ex-Russian spy. New York Times, Sept 6, 2018 (front page).
https://www.nytimes.com/2018/09/ ... chok-poisoning.html

Quote:

"Britain is one of the most heavily surveilled nations on earth, with an estimated one surveillance camera per 11 citizens. It has cutting-edge technology for visually identifying criminals, and software so sensitive it can scan an airport for a tattoo or a pinkie ring. And then there is that team of genetically gifted humans known as 'super-recognizers.'  On Wednesday [Sept 5], the authorities announced that the effort had paid off: Two Russian intelligence officers had been charged with attempted murder,

"Investigators released a cache of evidence, including security camera images * * * They also released photographs of the delicate perfume bottle that was used to carry a weapons-grade nerve agent, known as Novichok, to the quiet English city of Salisbury where the attack took place.

"John Bayliss, who retired from the Government Communications Headquarters, Britain's electronic intelligence agency, in 2010 [said,] 'And with the new software they have, you can tell the person by the way they walk, or a ring they wear, or a watch they wear. It becomes even harder.'  The investigation into the [Russian defector Sergei V] Skripal poisoning, known as Operation Wedana, will stand as a high-profile test of an investigative technique Britain has pioneered: accumulating mounds of visual data and sifting through it.

"In the days that followed the Skripal attack, investigators began by collecting 11,000 hours of video from ports, train stations, shop windows, car dashboards and the roadways around Mr Skripal's house.  Before searching for a needle, investigators said wryly, they first had to build their own haystack. * * * Those results were then overlaid with passport data for Russians who left the country shortly after the poisoning, bringing the pool of suspects down to a manageable number. The police were able to cross-reference suspects in other ways, mapping mobile phone and bank card use, for example.

"Investigators had one bit of luck: Heavy snow fell through the weekend of the attack, reducing the number of people on the streets.

"A big breakthrough took place nearly two months after the Skripals were poisoned, when the police arrived at the City Stay Hotel in East London, where the two suspects had spent the two nights before the attack. Officers took samples from the room where the two men had stayed, and sent them for laboratory testing. Two of them showed trace contamination for the nerve agent used in the attack.

My comment: There is no need to read the rest. I am interested in methodology.