It is not a sentence; it has a serious structural flaw which I must fix before commenting: To the greatest extent possible, they sealed their world from the outside, locking out talk of Jews gone bankrupt and starvin g, of those who committed s uicide with veronal or by jumping in front of the S-ban or out some window. Now: the pronoun is by priority the subject of 'committed'. -- 'Who' is the subject of 'shot', and 'who shot her' (as a clause) is the object of 'know'.
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