I recently read D. H. Wolfe's 2005 The Black Dahlia Files: The mob, the mogul, and the murder that transfixed Los Angeles. (New York: ReganBooks). I've read just about every book about Elizabeth Short (the Black Dahlia), but I never thought about where the files about the case are archived. The book notes:
As a rule of law, unless there is an indictment that stems from a Grand Jury investigation, the files are sealed and never made public; however, in the Black Dahlia case, some of the Grand Jury investigation material inadvertently became accessible in 2003 when the Los Angeles District Attorney’s Office established its archives and opened up to researchers some of its files on notable twentieth century criminal cases. Among these files was a portion of Grand Jury investigator Frank B. Jemison’s file on the murder of Elizabeth Short. This unintentional disclosure of Grand Jury proceedings and testimony proved to be a windfall of new information that had been hidden from the public for more than half a century.and
In speaking to a former file clerk who handled the assembly of the files for the archive, I learned there had originally been sixty-five file boxes of accumulated Black Dahlia investigative material, which included the files for the LAPD, the Sheriff’s Department, and the District Attorney’s Office. The file clerk recalled that the sixty-five boxes were culled through in the early months of 2002 and reduced to thirty-five boxes, which remain in the LAPD warehouse. But two file boxes involving Jemison’s 1949 Grand Jury investigation into the Black Dahlia case were among those placed in the archives of historical criminal cases at the D.A.’s office (267-8).
Some of the material found in Elizabeth Short’s lost luggage by the Examiner was returned to [her mother] Phoebe Short, but many of the photos of Elizabeth ended up in the Examiner Archive, which was donated to the Special Collections Department of the University of Southern California in 1988. Most of these photos vanished from the USC Library in the early 1990s and were eventually auctioned off on eBay in 2002 (footnote 6, 86).Some of the images of her in the book cited the Medford Historical Society because she grew up in Medford, Massachusetts; the Delmar Watson Archives, the LA-based new photographer; and UCLA Department of Special Collections/John Gilmore Collection. Gilmore has written about the Black Dahlia, and the collection has an fascinating finding aid.
I also found an article about the Black Dahlia being the most-researched topic of the USC collection.