[fwdude]

None of what you mention is included in the original post. Furthermore, there is no way for me to look up any reference.

[Haiku Guy]

The Wikipedia entry for the Smolensk Cemetery is interesting. But it does not include this particular detail.

[annalex]

The head post was somewhat cryptic, I apologize. On the other hand, some images came to symbolize the horrors of the 20th century, are well known and instantly recognized. But there is no such symbol for the Red Terror. Yet, people walk around and, suddenly, see bullet marks.

I subsequently provided some Wikipedia articles in #11 and #12.

You also asked if those people were killed "by virtue of them being Christians, or on identity politics?"

The Soviets, or, more accurately the Reds (the "Soviet" label started to be assumed by them in about 1922 when the Soviet Union was formed), recognized, correctly, that any religion would be an enemy of the new Socialist state. Since the Russian Empire was, at its core, Russian and Orthodox Christian, the terror was directed primarily at the Russian Orthodox Church. But the Reds made no distinction between particular forms of Christianity or ethnicity, they simply shot (or tortured to death) those who opposed the looting of the churches, or preached against them.