Russian Oligarch Found Dead in Moscow after Falling Out of Window

The classics are the point. These aren't meant to be secretive killings, the signature is the message.

They would use a different method if they wanted to obscure responsibility, dispose of the body, or do any number of things differently. Because they didn't, means it was a public signing statement.

Whether it was intended for one recipient, or many, who's to say. Either way, you can be sure the intended party, or parties, received it.

Windows are just so unsafe in Russia, aren't they? I'm never getting near one if I ever going to Moscow.

Well. You'd need to avoid windows, tea, people with umbrellas (OK not directly Russian, but soviet era eastern europe), aeroplanes, cars. And if they really want to get you, they'll go old school and use a gun, or perhaps even a missile if you annoy the right people enough.

I'd just skip Moscow as a whole personally.