Could draw a parallel to Nick Broomfield's Tales From The Grim Sleeper, from the perspective that the bodies were allowed to accumulate because the target victims were from a marginalised group within society. In the former, the victims having been prostitutes, and in the latter being young gay men in 1980s Britain. You tend to think of policing as based on science and with the highest levels of professionalism applied, however this is pretty far from the truth. Both biases and discrimination playing a major role in outcomes. Maybe the biggest divide of them all is class inequality and how that affects victims and perpetrators. Its fairly well made but I felt it could have been longer and gone more in depth in to the psychology of Nilsen. More often than not documentaries tend to avoid doing this, as I guess looking deep in to the mind of a mass murderer isn't essentially positive for the greater public good. There seems to be a lot of audio and writing from him though, and i did feel in the end that aspect of the doc was cut short in this instance, as he seemed to have an awful lot to say for a serial killer.