A relevant post at another_kashin (in Russian), the LiveJournal of journalist Oleg Kashin (the news report he's citing differs from the one I've read, though - I thought the murder took place down at the station, not near it):

Today

Itar-Tass Agency reports that a young man resembling a skinhead attacked an Armenia native and stabbed him many times with a knife near the Pushkinskaya metro station. The man died of injuries on the spot. After the attack, the bandit went down into the subway. The search for the criminal has begun.

It has been reported that the attacker was 18-20 years old, his head was shaved, and he was wearing a black jacket and black cargo pants. According to the law enforcement officials, the criminal is very dangerous.

I was at Pushkinskaya on my way out into the city at the time the corpse was lying there. Indeed, a kavkazets [a Caucasus native] and somewhat too cut up. Little fences were placed around him, inside the fenced area two Slavic women sat, and across the central hall cops were holding hands and solemnly looking around, like they do at [Lenin's] Mausoleum. To pass the cops, one had to go up toward the Gorkovskaya pass, and then go down the adjacent staircase. This is what I did. Turned around to look at others. People are walking, talking, smiling, then look at the Armenian, and their jaws drop.

I told the cab driver about it. The cab driver laughs - well, our dear skinheads again, great.

What follows is an attempt to discuss the term kavkazets:

[...]

sumlenny: "kavkazets" is one of the most stupid terms for a commentary like this. The victim was an Armenian. Any average Azeri (also a "kavkazets", according to your classification) will be cheering his death more than some Russian fascists.

[...]

object: Any [Azeri], aha. Any.

sumlenny: ok, lets say "many [Azeris]." Do you remember how during a joint NATO training an Azeri officer "lost patience" and killed his Armenian fellow-trainee with an axe?

In any case, the goal of my comment wasn't to insult Azeris. I was drawing attention to the fact that there is no such entity as "kavkaztsy". Only for a journalist sitting in his ivory tower do the look the same, just like the Japanese, Chinese and Koreans do. But a Chinese would be very offended if you call him a Japanese.

object: For those who killed this poor Armenian, such an entity does exist, I think. After all, they don't ask for the passport [to learn the victim's ethnic origin] before attacking.

And here are some more reactions:

krumhilda: A nightmare... I'm more shocked by the people's reaction than by the corpses. Though that's monstrous, too.

lukyanich: Armenians like us [Russia], the only ones in the Caucasus, all the more a pity, a skinhead has bumped off a Christian. Perhaps time to bump the skinheads off, eh?

ac_diver: very likely that this will start happening soon... i heard today that (in Petrozavodsk, I guess) in a fight between "kavkaztsy" and skinheads, they did kill one skin... There's one question in this situation - who will these "kavkaztsy" consider as belonging to the entity of "Russians"?

rusliner: Violence begets violence. Do you need that?

sumlenny: what you've said is nonsense. Violence can as successfully - and sometimes even more successfully - be brought on by the lack of resistance to violence.

rusliner: I'm not calling to ignoring violence! But to respond with violence is only possible when ALL THE OTHER means have been exhausted. Otherwise, I won't see any difference between sides.