I would totally recommend you this series if you're passionate with crimes and psychology. I felt like the producers were into characters, it was surprising how I was able to understand the pain of the characters. They expressed well human behaviour and their psychology. Some character speaks Taiwanese, and it made it seems like a complete universe (I understand mandarin, so it made me feel like the series' world was not from our world).

As for the second season, it is hard to understand. I had to do research to understand better.
It's long but worth to give it a try!

(Please watch the first and the second episode before giving up!)