Fiscalía in Spanish refers to a district attorney or public prosecutor. "Fiscal" (in English or Spanish) describes something related to finances. This always confused me because the words are very similar but seem to have fairly different meanings. Are the two related? What is the etymology of fiscalía?
Fiscalía refers to the office of a district attorney or public prosecutor rather than the attorney / prosecutor itself. The attorney / prosecutor is a fiscal.
I can't tell you much about etymology, but both words are indeed related and I think they derive from fisco, which refers primarily to the treasury (as in the US Treasury).
For what is worth, wiktionary says this about fisco:
Fiscalizar is also another common word with the same origin, meaning to supervise or to control (for instance, an election to prevent fraud; generally, at least in Argentina, the parties involved in an election send fiscales to the polling stations).