As the world contemplates the various 'provocation' scenarios - a Russian act, a CIA act meant to look like a Russian act, or a Russian act meant to look like a CIA act? - the following clip suggests this was anything but an ad hoc shooting...

The narrator suggests, as Nemtsov and his companion are walking along the road, a garbage truck (or cleaning vehicle) is behind them. When the garbage truck comes alongside the couple, it slows down, then moves ahead, then stops... and another man leaves the vehicle and jumps in a following car, which speeds away with tires smoking...

* * *

As Ukraineatwar blog concludes,

The video seems to be real, because the location EXACTLY fits the know murder spot. It does not seem likely that such a video could have been prepared in advance.

The murder EXACTLY takes place when the cleaning vehicle passes by. It is absolutely unclear where the assassin come from. Nobody can be seen walking towards or behind Nemtsov and his companion. Neither can somebody be seen walking to that specific spot to wait for them.

Therefore it seems very likely that the cleaning vehicle has something to do with it and the assassin could have traveled with the vehicle.

Since Nemtsov was shot from behind and the cleaning vehicle already caught up with them when the murder took place, it does not seem likely that the assassin traveled on the passenger seat next to the driver. He had to open and close the door and that may have drawn their attention. It seems likely that he had traveled on the back of the car. He could easily jump on and off and could also estimate if there were other people to close to them to do the operation at all at that moment.

Using a cleaning vehicle gives a lot of advantage: you can drive slowly, draw no attention, wait if necessary and thus pick exactly the right moment (with no other people nearby).

It does seem like the assassin had been following the couple already when he jumped on the vehicle. They may have crossed the road where the cleaning car was waiting. After seeing them pass by, it started entering the bridge. When they passed the assassin, he jumped on. In this way they could be sure that they had the right person AND they could pick the right moment without running to catch them up.

All the getaway car had to do was to wait until the cleaning vehicle got on the bridge, see the hit man jumped on and then get to follow from a distance to slowly catch up.

It all does look like a REALLY WELL orchestrated operation.

Totally weird is that there is no traffic at all behind them. Such a moment is very hard to pick, especially when you can see that there are many cars before the assassination moment. Right after the car picks up the assassin, new cars start arriving again. This indicates there had been some 'orchestration' here too. Either traffic lights had been red on all fronts or traffic had been halted in another way.