I propose considering the player with the nickname nik312 as a suspect in the WisTrit murder case. The logic is simple:
1) Recall the name of a relatively well-known musical group called Gorod 312.
2) Check the profile of the aforementioned player.
3) Correlate all of the above with the clue from the first murder.
Best regards,
Gur
Хай Гурий Слесарь