There could be a number of potential connections between John Houston and the Black Dahlia story. If we consider the context of the time, both were part of the Hollywood scene in Los Angeles during the 1940s. The Black Dahlia case was a huge scandal that rocked the city. Houston, being a filmmaker, may have been aware of the case on a social level. He might have even considered making a movie about it, as many filmmakers are drawn to true - crime stories. However, there is no evidence to suggest that he actually did. Also, the general sense of unease and the darker side of Hollywood that the Black Dahlia case brought to light could have influenced the themes and tones of Houston's films, even if not directly related to the case itself.
The Black Dahlia case is a well - known and tragic unsolved murder mystery. John Houston was a filmmaker. It's possible that in the world of Hollywood and the seedy underbelly that the case exposed, there could have been some form of indirect connection. Maybe Houston knew some of the people involved peripherally, or perhaps the case influenced the atmosphere in Hollywood which in turn affected Houston's work. But again, this is all speculation without solid evidence.