and I don't think they would kill me, because she's not alone in the mafia, so no need to play the protector here))
if we consider the coins (which are almost 100% clues), then there are three suspects: Neyra, ZUBR, and Kostyan, + each of them has a clue from the text.
Added 3 minutes later
and maybe it was him who killed (sinned), that's why he went to buy an indulgence.