By John Helmer, Moscow
In cases like the poisoning of Sergei and Yulia Skripal, the only way to proceed is by identifying the evidence which proves with certainty what happened; or failing that, proves with certainty what did not happen. Perpetrator, co-conspirators, method, motive, intention – all come later, if they come at all.
At the moment, according to police and government releases and the British state media, the crime scene in Salisbury is being combed by at least 250 police officers; with another 180 military personnel specializing in chemical warfare. Dozens more electronic surveillance and cyber-warfare agents are also engaged. The crime scene locations include the Skripal house; the cemetery graves of Skripal’s wife and son; the Mill public house where Skripal and his daughter had a drink; the Zizzi restaurant where they ate before collapsing; and the public areas where they walked between house, pub, restaurant, the Maltings shopping precinct, and park bench.
At least 240 pieces of evidence have reportedly been identified as such, not counting the Skripal house, and 200 witnesses interviewed, including Wiltshire Police Detective Sergeant Nick Bailey. He developed symptoms after being despatched to the Skripal house. That is, after the Skripals had been found and hospitalized.
According to Lord Ian Blair, a former Metropolitan Police Commissioner, “there are some indications that the police officer who was injured had been to the house, whereas there was a doctor who looked after the patients in the open, who hasn’t been affected at all. So there maybe some clues floating around in here.” Blair said this on the BBC.
His disclosure, also confirmed  in several newspapers, provides the first certainty in the case: the Skripals came into contact with the poison for the first time inside their own home. They then went out to the pub and the restaurant. Certainty No. 2 – the poison cannot have been fast-acting for them at home. Certainty No. 3 – the poison was faster-acting for Sgt Bailey because he developed symptoms almost immediately at the Skripal house.
Follow the next eleven certainties.
Certainty No. 4. Prime Minister Theresa May has identified the poison as a “military grade nerve agent…part of a group of nerve agents known as Novichok.” Listen to May making her announcement  in the House of Commons yesterday.
Certainty No. 5. Novichok components are harmless until they are combined. Once that is done, and the mixture dispersed, the poison acts swiftly to attack the nervous system, triggering heart and lung failure, and death by suffocation.
Note: the Soviet development of Novichok was designed to be undetectable by NATO standard chemical detection equipment. It is not certain how the British could detect an undetectable Russian substance; read more .
After they had left their home on Sunday afternoon, the Skripals spent more than an hour before developing symptoms. It is certain, therefore, that there were two sites of active poisoning. The Skripals must have carried the poison from their home through the streets to the mall, the pub, and the restaurant, before they were exposed. The large numbers of police, special service agents and soldiers have been deployed in order to trace the route the Skripals took, and all points at which they stopped, in order to identify, measure and map all concentrations, then dilute or destroy them for public safety.
Certainty no. 7. The British forces have inventoried all contents of the Skripal home, and verified all deliveries to the house, including mail and packages before last Sunday. They are certain to know if there are traces of the chemical components required for the Novichok combination, and whether these traces are in separate locations of the house. It is certain they have asked themselves how the nerve agent was active in the house to strike Sgt Bailey, but inactive for the Skripals until hours later.
Certainty No. 8. The British secret services and the Porton Down Defence Science and Technology Laboratory near Salisbury know what contact, if any, there has been recently between Skripal, his British secret service contacts and the Porton Down lab.
Certainty No. 11. Although the British, American, and Russian secret services have the electronic capability to have been monitoring the Skripal house, Yulia Skripal on her travel from Moscow to Salisbury, and Sergei Skripal at home, in advance of the poisoning, they are unlikely to have been doing so on Sunday afternoon. British sources add that the security perimeter for the Porton Down establishment doesn’t extend the nine kilometres (twelve by road) to Salisbury town.
However, it is certain, the sources acknowledge, that in retrospect the British and American services will have identified all unusual mobile telephone, other electronic signals and encrypted messaging around the Skripals on Sunday, including computer, internet and mobile telephone signals the Skripals sent and received before the Sunday events. Just as certainly, the Russian services will have the retrospective capacity to follow the communications of all their agents in the vicinity, if any there were. It is sure that if there had been a Russian operation targeting Skripal, an unusual volume of electronic evidence would now be visible to the British and Americans — and the Russians would know it.
Certainty No. 12. The Russian Foreign Ministry has not yet summoned the British Ambassador, Laurie Bristow, to present the electronic evidence — if the British Government has it. Alexander Yakovenko, the Russian Ambassador in London, has yet not been to the Foreign Office to request the Foreign Secretary’s evidence. Nor has he been recalled to Moscow for consultations, yet.
 Certainty No. 13. The Russian Security Council  has not been called into formal session since February 26. This two-week gap is an unusually long one. It is certain that President Vladimir Putin has requested Council members Sergei Lavrov of the Foreign Ministry, Sergei Shoigu, the Defense Minister, and the heads of the security and intelligence services to report what evidence they have; their assessment of what happened to the Skripals; and their view of the seriousness of the Skripal case for Russian state interests.
 Half-certainty. Sir Andrew Wood, 78, was the British Ambassador to Russia between 1995 and 2000. Since then he has been making his living selling opinions on Russia to commercial organizations and think-tanks. He has also been caught lying in public about his commercial involvement with Christopher Steele, and the role the two of them played together during the American presidential election campaign to accuse President Donald Trump of improper collusion with the Kremlin. Wood’s story can be followed here . On March 10, the Guardian reported Wood as accusing the Russian intelligence services of an official assassination attempt against the Skripals. “I don’t doubt”, Wood told the newspaper, “[the poisoning] had general approval from senior heads – that’s the system he’s [Putin] created. Since 2012 Russia has been going backwards, rejecting economic reform and better courts in favour of renewed state control and repression, a fear of anything that is other. It’s the revival of Stalinism and the idea that Russia has the right to dominate its neighbours.” Read the newspaper report  in full. It is certain Wood had no evidence to substantiate his allegation at the time he spoke. It is equally certain he had no doubt of it. With Wood’s record for veracity, these two certainties add up to a fraction less than one.