Adeano -
I see by your #30 that you've cracked the title - '"...an alternate phrasing of the thematic pair! Lovely!"
Please do (discreetly) share your insight - which "thematic pair" do you mean - the 'perpetrators' or the 'perpetration'?
I've looked at thematic translations, lists of synonyms - nada.
I know it doesn't mattter, but it's bugging me...