Kostya | Ayda

The volunteers are essentially used as expendable material by the police, just as organized crime groups use their small change. So Kostya isn't a "good cop in a bandage," but part of a system where everyone has dirty tricks.

The KAI BKD had existed since the 1960s; its fighters died during raids (Artem Aidinov in 1965, Igor Assman in 1969), and in the 1970s, the squad directly confronted Tyap-Lyap and similar groups.

For street kids, the Komsomol militia is their main enemy. That's why the militia's appearance is both a salvation for Grisha and a cause of further trouble: in the street world, any connection with the "other side" is perceived as a betrayal.

The BKD isn't a gang, but its opponents. They are the Combat Komsomol Squad: volunteer units of students from Kazan universities (the most famous being at the Kazan Aviation Institute), who patrolled the streets, broke up neighborhood fights, and apprehended hooligans—in coordination with the police, but essentially as their own unit.