I don't know anything about this show outside of the show itself, so I don't know if it's common knowledge what the series will eventually do with all the BTK teases, but for me, watching the show, the teases are a bit of a letdown.
From the final S1 episode to the first few eps of S2, I definitely had the impression the BTK was going to be foregrounded in S2.
Weird and disappointing that, once again, the season ended with BTK tease. I guess it's all leading to a S3 where the BTK will be the main arc? Again, don't know cuz I don't read about the show.
Overall, S2 was IMHO plodding and disappointing, with needless, trite character backstory digressions (the detective must CHOOSE BETWEEN HIS FAMILY AND HIS JOB, the lesbian agent has TO BE CLOSETED, etc.), and a general lack of dramatic tension.
Also, wtf with the dark dark dark cinematography? I have a blacked out dedicated home theatre, and, man, there was so much I just could not see...I know the subject matter is "dark," but, like...I can't see the actors, lol.