I knew the case of the mysterious death of JonBenét Ramsey from podcasts. At first view, the case is like hundreds of others - the child goes missing, no one knows anything, no one has saw anything, so the parents are suspects. The difference, however, is that here the police literally did everything not to solve the investigation. They make a lot of mistakes, and while collecting evidence, they forget why they were summoned.
Could we find out who killed the girl if only the police did what they should? I don't know, but it would be nice if the police were not extremely incompetent in such delicate cases.
The documentary doesn't talk about anything that hasn't already been said. However, it's a very good summary of the investigation, the collected evidence and the theorys about the girl's death (perhaps focusing too much on one of the theories, but still).
It's sad to watch documentaries like these, because they remind us that sometimes the perfect crime is the result of a lack of knowledge and investigative skills, not a calculating villain with super intelligence.
It's worth watching, but it's even better to google the case and listen to a podcast about it (for example, "Deception Detective", who recorded 7.5 hours of material on the subject), because Netflix, as usual, omits a lot of police negligence, and oversimplifies some threads.