"Beware the Slenderman" looks like it might fill the bill.
On Friday, HBO released the first terrifying trailer for the upcoming documentary, which tells the story of Morgan Geyser and Anissa Weier, two 12-year-old girls in Waukesha, Wisconsin, who stabbed a friend 19 times reportedly to appease an internet legend called the Slenderman. The crime took place in 2014, the victim survived her ordeal.
The unnerving trailer begins with a haunting rhyme about the Slenderman, who was created as an internet meme in 2009. It then switches to the apparent reporting of the discovery of the victim. The dispatcher is in disbelief; he has to ask the caller to repeat the report.
The trailer mixes explanations of the faceless, freaky Slenderman legend with details of the case, which is still in progress.
"Beware the Slenderman" doesn't have a release date.