I wonder if he considered himself safe. He should have. He'd served his time, he'd been pardoned and he hadn't raised his head above the parapet to criticise Putin or his administration since making his home in England.
However, a British Russian expert who is writing a book on Vladimir Putin's Russia since 2012, says the Russian President has made no secret of his loathing of traitors. He claims Putin has actively encouraged the secret service to hunt down terrorists and dissidents based outside of Russia and points to the assassination of a Chechen rebel leader in Doha and the horrific death of Alexander Litvinenko in London as examples of Putin's influence.
So this is not really a whodunnit - everyone from the commentators quoted in the media through to the local butcher and the two ladies travelling behind us on the 219 bus believe it was the Russians.
However, as aficionados of Midsomer Murders know, the obvious suspect isn't always the killer. After all, why would Putin wait so long to do away with a bloke he could have kept in prison?
If Skripal was such a threat to the Russian state, surely he could have been disposed of far more discreetly on Russian soil. Maybe Skripal's quiet life in Salisbury was a cover for continued dodgy dealings and undercover goings on?
There are many questions, but what the authorities do know is that the damage was done by a nerve agent to the father and daughter. They remain critically ill in hospital, as does the police officer who administered CPR to the father and daughter when they collapsed outside a shopping centre last Sunday.
Nerve agents aren't something your average DIY terrorist can whip up at home.
Apparently, these sorts of things are produced by experts in specialist laboratories under the control of governments - so again, the Russians are implicated.
The Remainers, those who wanted the United Kingdom to stay within the European Union, are huffing and puffing and suggesting that England is now a sitting duck for any country or extremist group that wishes it harm, having lost the protection of the EU and without a strong working relationship with the United States.
But really, how do the Remainers explain away the many suspicious deaths on British soil that American intelligence agencies have linked to Russia?
Media reports suggest up to 17 deaths could have been perpetrated by Russian agents - they seem to be able to enter the United Kingdom at will and exact their revenge on those on the authorities' hit list.
The question is what should the British government do now? Looks like a Russian, smells like a Russian but the British pride themselves on the tenet of innocent until proven guilty.
The British Prime Minister Theresa May says the investigation must run its course but if it is found that the Kremlin was responsible, expelling the Russian ambassador is an option. And the Foreign Secretary Boris Johnson has threatened to withdraw the British delegation, if not the English team, from the World Cup being held in Russia in just a couple of months.
It all makes for fascinating reading over the tea and toast in the morning, but I have to remind myself that these are real lives and real-world politics in the balance.
This isn't some work of fiction and it's not a case that Miss Marple or DCI Tom Barnaby would be able to solve in an hour of television.
