By and large, a thoughtful documentary. The emphasis was, rightly, I think, on the actual process of investigation with the two main detectives front and centre. It gives a really good idea of the emotional and psychological pressures on those doing these sort of investigations - often harder to deal with for their familes than themselves. And of course the victims families and survivors - some enormously impressive people seen here.
The practicalities of the cases are fascinating - for instance the fact that fingerprints had to be compared by eye alone as they were not on an electronic database and the problems of jursidictional overlaps where killings happened in a wide range of areas, came across very clearly. I hope that now these have been more or less solved….
We see little of the perpetrator until the final episode and even then he was just a looming background presence of chilling power.
The only downside is that at times the film did become somewhat stylistically melodramatic - particularly in the first episodes when almost invariably there would be a ‘significant’ lingering shot on a character either before or after they spoke. This was quite unnecessary and I felt that it cheapened the film to a degree. Likewise the over-use of popular music on the soundtrack which too often unnecessarily underlined points that were being well and effectively made by talk and or images. It was over-egging the pudding which made it a bit more difficult to digest.
But finally, pretty well done, in spite of minor strictures above.