OK, so apparently the alleged killers weren’t from Chechnya but rather from Ingushetia. Dadayev, however, did serve in the Chechen battalion “Sever”.

meduza.io

Dadayev’s mother of course doesn’t believe the accusations. The Kubashevs that were arrested with Dadayev are apparently her nephews, so those are all relatives.

The mother says that Dadayev was fighting against Wahhabis for 10 years.

Which, again, would tend to point away from “Ichkerian terrorists” or “ISIS agents” hypotheses that some pro-govt individuals have posited.