The Atticus Institute is a found footage movie that purports to be based on a real case, but is any of it true? Cannibal Holocaust from 1980 is the first real found footage movie and followed a documentary crew who antagonize and finally get eaten by a cannibalistic tribe. The movie remains truly disturbing to this day and proved shocking to audiences during its original release. The blurring between movie and documentary proved groundbreaking but it was The Blair Witch Project that truly proved brought this subgenre into the light.
The Blair Witch Project also used the internet as a marketing tool, which was a novel approach back in 1999. The next big landmark in the genre was Paranormal Activity and the genre soon became swamped in entries, including Cloverfield, George A. Romero's Diary Of The Dead, As Above, So Below, and many more. These movies tended to vary greatly in quality though, and the format was sometimes used simply as a way to make cheap, easy to market horror movies.
One of the more interesting concepts for a found footage movie to arrive in recent years is 2015's The Atticus Institute. The story is set in the 1970s and takes place in the titular institute, where doctors are looking for proof of abilities like telepathy. They study a woman named Judith (Rya Kihlstedt, Call of Duty: Modern Warfare), who does very well in their various tests but it soon becomes clear she's possessed by a demonic being. They call the government in for assistance - who seem more interested in turning the demon into some kind of weapon.
The Atticus Institute's commitment to the documentary format is one of its strengths, and it features a mixture of vintage footage from the 1970s with photos and retrospective interviews. The story sells itself as being the only case of demonic possession recognized by the American government as the real thing, but the movie itself is total fiction. Director Chris Sparling (Buried) feels the angle of a possession movie where the government comes in and tries to weaponize the subject was a unique angle and worked from there, so it wasn't based on a true case. That said, it was somewhat inspired by real-life government investigations into psychic abilities during the 1960s and 1970s.
The Atticus Institute's story hook is a compelling one and the movie is lean in terms of runtime, but it doesn't quite reach its potential. Its commitment to being authentic gives it a creepy edge, but then it falls back on familiar tropes from both the found-footage and possession genres to provide scares.