they have abandoned me

Here the word "they" refers to the people of Judah.

filled this place with innocent blood

Here "innocent blood" represents the murder of innocent people. Yahweh speaks of murdering many people as filling a place with blood. Alternate translation: "murdered many innocent people in this place" (See: rc://en/ta/man/translate/figs-metonymy and rc://en/ta/man/translate/figs-metaphor)