Despite some minor blips here and there throughout the movies, I have to say I rather enjoyed this series, and I'm looking forward to part 9. I do feel like, at this point, the title should be changed, but it is what it is. I guess it would be too confusing to change it now, since no one would know what to look for when trying to watch anything after the first couple films. But most things were done well, and the activity does put me on edge a little. Despite the information below the spoiler warning, I would recommend this series, if you can ignore the blips I've mentioned. Other than those blips, the series is quite realistic. I went in knowing it's a fake documentary/found footage, but I've read that quite a large number of people have thought it was all real.
With that all being said, this is a series I'd probably re-watch when bored and unable to find anything else. And I'm pretty picky when it comes to movies, so I would definitely give these ones a try. Part 5, you'll most likely have to rent on Amazon, though. The rest can be found on free streaming sites such as plex and possibly tubi.
**POSSIBLE SPOILERS AHEAD**
The only issues I've had with the films, and only really the later ones (I think just parts 7 and 8, but possibly 6 as well) is that it's supposed to be documentary/'found footage' style. However, some parts that are done with a drone or shots taken of of Turner's face at some points, are most certainly not shots he's taken with the cameras he's using throughout the movie and talking to. I'm not sure if these shots are just for dramatic effect or to show pleasing, aesthetic scenes, but it does take away from the immersion and seriousness of what's happening.
Additionally, how the police act in some situations just doesn't make sense and it makes Ramey and his team look insanely dumb and unreliable. Even if 2 pieces of evidence seem identical, would common sense not tell you something's off about that? It was as if analyzing the evidence further was some special procedure that wasn't often done and therefore the police didn't think of doing so. Especially considering the culprit is too smart to do something so dumb, you'd think they'd have the same idea as Turner without him saying it, and be like 'Oh, maybe the guy has added something else to this seemingly identical piece of evidence'. To add to that, there's a perfect opportunity for them to make an attempt and arrest the culprit, and yet they refuse to go along with that idea, which is ultimately a mistake. Would police not normally jump for that chance, considering the guy had killed his first victim around 50 years prior to part 8? I'd think they'd want to get that guy any chance they got and put him behind bars.