Jenny Popplewell’s slickly made “American Murder: The Family Next Door” only spends a few minutes analyzing those awful days when people and pundits took to TV and the internet to announce that Shan’ann deserved to be killed, but her true-crime documentary also hinges on the same information so many used against her. An impeccably produced look at a heinous crime, Popplewell’s documentary meticulously weaves together a wealth of information — including body-camera footage from the first cop on the scene, claustrophobic interrogation room setups, and the social-media messages so many armchair sleuths pored over to discredit Shan’ann — that it almost feels too readymade for the film treatment. Almost.

Anyone with passing familiarity with the Watts case enters the documentary from a strange point, and it’s one that Popplewell doesn’t try to deflect: We already know the murderer’s identity. While Popplewell doesn’t worry too much about interrogating Chris’ motives (really, what motive could explain family annihilation?), the filmmaker does lay out one hell of a case against him long before he confesses to the murders. The crime seemed tailor-made for easy consumption: a lovely young (and white) family, seemingly happy and well off, is cracked wide open when mother and babies go missing, leaving attractive father begging for them to come home. Popplewell’s film attempts to build that story from the inside out, opening up with a slick, social media-heavy setup that brings us into the lives of the Watts family and then implodes them as the case (and the truth) reveal themselves. The doc recreates Shan’ann’s own packed Facebook page and her busy text message and call logs, and has more in common with a “screen film” like “Searching” than much of its true-crime brethren (“Tiger King,” this is not). Popplewell soon adds body-cam footage, neighbors’ security videos, Google Maps overviews, and personal video taken by Shan’ann’s friends. The result is an immediately immersive story, but it can’t help but feel a little too well designed. Since so many people record so much, “American Murder” has more than enough to craft a story — but often, the truth lies elsewhere. Seemingly spontaneous asides from minor participants prove to be more illuminating than many of the film’s more rigidly designed sequences. There’s the jittery neighbor with a key security video who is the first person to say that Chris is acting strangely, the cop who tags along for a delayed search of the house who is struck by just how clean it is, and a polygraph administrator who, upon their first meeting, provides more insight into Chris’ character than his closest compatriots could ever offer.

Slowly, Popplewell builds her story (and the case against Chris), abandoning a straightforward timeline to zip into the past to fill in gaping questions. When inquiries into the state of Chris and Shan’ann’s relationship flow into years-old video of him giving a speech on deteriorating relationships, you have to wonder: Is everything on video? It’s enough to make a very real tragedy seem like, well, any other kind of entertainment. Perhaps that’s the point. Popplewell’s film doesn’t grapple with the implications of its own assembly, but the presentation of such personal material can’t help but leave a mark. Shan’ann’s play-by-play texts that narrate the crumbling state of her sexual relationship with Chris feels intrusive, especially when the audience already knows that Chris was having an affair. Maybe this level of access can redirect a narrative that spun wildly, horribly out of control after Shan’ann’s death, turning the camera back where it belongs: on the victims.

Grade: B

“American Murder: The Family Next Door” will start streaming on Netflix on Wednesday, September 30. Sign Up: Stay on top of the latest breaking film and TV news! Sign up for our Email Newsletters here.