There's no ambiguous ending with this show because it's not about catching a single serial killer. All the serial killers are already behind bars. It's really about the birth of the criminal profiling unit at the FBI in the 70's.I can't get into these shows that leave the ending ambivalent. It's a cop-out. Either the show runners wrote themselves into a corner (American Vandal) or they want you to tune in next season, either way it feels manipulative.
A police procedural movie is fine (Zodiac), but a SERIES like that sucks. If I know it's not going to have a conclusion, I'm wasting my time. The character arcs have no ending. Bleh.
I dunno. I find it to be a refreshing take on the serial killer procedural. That could all change in season 2. I've already read about the next season planning to focus on the Atlanta child murders.