Kirby Johnson was able to portray a lot of the bodily contortions without CGI or prosthetics "in camera", due to her being a dancer, gymnast, and contortionist.
In the original script, the morgue was much smaller. Director Diederik Van Rooijen rewrote it to be much bigger, emptier and scarier, and also added the automatic lights.
The first Sony Pictures film to be shot on a full-frame mirrorless camera. Sony said that the film was primarily shot on its own A7S II, a consumer camera that costs a mere $2,000.
Was filmed in November 2016 but not released until the end of 2018. The long post production period was due to a change in management, and the new head of studio wanted some changes in the end result. Fortunately, director Diederik Van Rooijen had shot enough material to accommodate these changes.
Director Diederik Van Rooijen caught the attention of Hollywood with his low-budget thriller Taped (2012). He moved from the Netherlands to the USA with his family in 2014 to direct a remake of Alfred Hitchcock's Les Oiseaux (1963). However, the studio couldn't decide between a classical remake or a modern take on the material, so the project got stuck in development hell. In the meanwhile, van Rooijen got involved with The Possession of Hannah Grace, and decided to make it his American debut.