Being a person who is unaware about what happened at that time and try to get insight through this series, I feel like series is not narrated well the way it should have been, you get bounce off of the topic very often thinking that what director/narration wants to say about it. You get bored because you loose focus more often due to too much irrelevant facts are woven together at length and tried to justify dumb/incompetent investigation through situation of women during that time, industrialization problems, policing biased etc.
Main thing which caught my attention or rather I got convinced of the dumb investigation, policing biased, lack of cooperation and conviction towards catching the killer. It shows that police had put lot of efforts to catch the killer but that was just a donkey work due to biased approach.
It felt like they had lot of data to catch killer like hand writing, voice tape, even facial photofit and they had interviewed killer many times but they couldn't see beyond certain limit due to lack of openness.
I also felt that recent and past interviews which shown during series are like some good movie commentary. Each one glorified their story telling with big words and so. Every time they got some new information, they used to say "IT CHANGED EVERYTHING ABOUT INVESTIGATION" but actually nothing changed.
And one point to note that they caught the killer with sheer luck, accidentally and not by hard work.
Some people might say Police put lot of efforts but without proper end result it won't matter. It simply tells putting effort in wrong direction.
Anyways, RIP souls who lost their lives and God forbids such dumb, biased investigation.