Der VIII. Grad (2004)

In an art studio in Hamburg, a young woman's body is found hanging up. A man from a homicide squad has developed new electronic equipment that allows him to analyze exactly who the perpetrator was. He moves into the studio for a few days to better research and investigate. Completely isolated and together with a corpse, he becomes addicted to drugs and seems to gradually go insane. And because things have to get even harder, he has to deal with the loss of his girlfriend, to whom he was a stranger shortly before. The end leads to morbid self-knowledge.

Unfortunately the movie Der VIII. Grad is not yet available on HBO Max.