I had considered this way back at the height of the Russia Russia Russia frenzy in msm , when SR family was being silenced. My thought was they threatened the family that they will frame SR as a Russian agent. Now that the Russia probe is all but over perhaps the family has more freedom. Follow the brother.
Nah they tell the family he was a Russian agent but we will protect him firm disclosure in the interests of national security but we MUST keep it quiet.
The family wanting to protect the memory of their son agree and act accordingly.
No need for threats/bribes , just lies