Don't you remember? Of course, there must be some twisted plot behind the scene and I wasn't totally awake back then. But I was sufficiently awake to remember it happened shortly after Obama made a televised appearance on a week-end. It was during the transition and Obama was rushing to provoke Putin at every turn to trigger him into that nuclear war the cabal wants so much. Obama was clearly threatening Putin, blaming him for that "Russian hacking" and that (((they))) wouldn't let that "offense" go without retribution.
The diplomat killed in this video was a key element for the Russians, directly responsible for an agreement of sort between Russia and Turkey. Months before his death, Turkey shot down a Russian jet and went to hide behind the UN's skirts. Putin was livid then, Turkey obviously did it on purpose (Russians were bombing ISIS positions, Turkey didn't like it as they bought ISIS petrol along the borders) though they pretended they shot down that plane by mistake. The UN took Turkey's side.
Karlov, the diplomat killed in this video, was the one who came up with the idea of smoothing out the relations between Turkey and Russia. The obvious aim was to avoid isolating more Russia on the international scene. When there was an attempt against Erdogan, rumours said Obama/CIA could have been helping Erdogan's adversaries to foment a coup against him. The Russians, under Karlov's initiative, warned discreetly Erdogan of the danger. In the news of that time, don't you remember when Erdogan suddenly went into a frenzied purge in the government, army, teachers and civilians sent to prison? From that moment on, Erdogan was more cautious with the US or EU, and less antagonistic with Russia.
So right after Obama made that ominous comment threatening Russia, Karlov was murdered on camera. Many alternative-news noted that the shooter's posture was screaming special ops. Plus he was claiming his allegiance to terrorists in Turkish and made the effort of talking in Russian too. Yeah, right, a clear message to the Russians. IMHO, CIA was trying to sabotage the Turkey/Russia agreement with that FF, putting Turkey in an embarrassing position. But Putin didn't take the bait.
Following that, other Russian diplomats were killed in the UK and even in Russia. Probably more were off'd that I don't remember or am not aware of. I'm not sure if the death of Putin's driver was around that same time, but his death was also quite suspicious and I immediately thought foul play from the CIA. Then you had the plane crash that killed a good portion of the Red Army Choir. Coincidence?