Did Russia kill White Helmets founder James Le Mesurier? A former British army officer, Le Mesurier's body was found in Istanbul, Turkey, on Monday morning.

I ask the question for three reasons. Russia uniquely fits the motive, method, and means profile here. Russian President Vladimir Putin's government despised Le Mesurier, the apparent method of his death fits with Russian intelligence service tactics, and those Russian services have the particular means to have killed him.

Let's start with the motive.

Russia hates Le Mesurier because he was instrumental in establishing the White Helmets civilian rescue service. The White Helmets operate in Syria, helping to save civilians suffering under attack from Syrian regime forces and their Russian and Iranian allies. The Russians despise the White Helmets because they obstruct Russia from killing civilians to force the Syrian resistance into submission. Last week, the Russian Ministry of Foreign Affairs attacked Le Mesurier on Twitter, accusing him of being a British intelligence officer and a terrorist.

Now consider the method.

A newspaper well-sourced with the Turkish government, Milliyet, reports that police believe Le Mesurier fell or was pushed from a fatal height. The newspaper also says Le Mesurier's face was cut and that his hands and feet were broken. If true, that suggests a struggle and that Le Mesurier was pushed. That's notable because Russian government assassins love throwing people out of windows.

Throwing people from fatal heights is effective and has the pretense of being accidental. Second, befitting their broader assassination philosophy, the Russian intelligence services revel in using window-fall assassinations in a target's home or place of frequency as a calling card. Third, because each individual window assassination fosters a broader fear among other prospective Russian targets that they aren't safe in their own homes or offices. This fits with the Russian affection for covertly entering homes of those they wish to intimidate and moving things around. Each element finds roots in Russian intelligence service humor.

Finally, let's consider the means of action.

Russian intelligence retains a significant presence on Turkish soil. In part this is because Turkey is a nominal NATO ally, in part it's because Istanbul is a major global intelligence playground. But while the Syrian and Iranian intelligence services share in Russia's motive against Le Mesurier, their officers and agents would struggle to conduct an apparently clean kill such as this. They would also fear significant political blowback from Turkish President Recep Tayyip Erdoğan's government.

Conversely, with Erdoğan now submissive to Putin's whims, the Russian services now have significant latitude to operate more aggressively in Turkey. So if Le Mesurier was killed, and if the Turkish authorities find evidence of Russian culpability, Putin will have good reason to expect Erdoğan to cover this up. This is both because Erdoğan will want to keep Putin happy, and because it would be embarrassing for Erdoğan to admit the Russians did this in his home city.

The ultimate point is this: Absent evidence established to the contrary, Russia should be regarded as a primary suspect in Le Mesurier's death.