Edit: I am curious if there is any precedent for this detail in the show, especially in terms of largely domestically based criminals. I have never really heard of or thought of Western Europe as a place where torture is commonly used in matters of national security, I have always thought that was more America's domain within the West.
Only reason 2000 is the latest is because of the sub-enforced cutoff, as the show takes place in 2019 or so.
While it's not about Spain, you may be interested in this fantastic answer by /u/Bernardito on France's systematic use of torture during the Algerian War (1954-62) and later debates on it, which seems very relevant to your question.