In the 1940s, the police and the press lived in a symbiotic relationship. Reporters used the cops for inside scoops and the cops used reporters to disseminate information to the public that they hoped would help solve crimes.
In the Black Dahlia case, detectives gave the Los Angeles Examiner fingerprints lifted from the dead woman and reporters used their "Soundphoto" machine — a precursor to a modern fax machine — to send enlargements of the prints to FBI headquarters in Washington, D.C.
FBI technicians compared the prints with 104 million fingerprints they had on file, and quickly made a match to one Elizabeth Short. Short's fingerprints were taken for a mail room job she'd had at an army base in California — and for an arrest record for underage drinking in Santa Barbara.
The FBI also sent the paper Short's government application photo. When reporters saw how attractive the 22-year-old victim was, they knew they had a sensational tale on their hands.
This was news noir at its best. To juice up the story, Examiner reporters resorted to an unethical ploy; they called her mother, Phoebe Short, and told her that her daughter had won a beauty contest. After prying as much personal information about Elizabeth from Mrs. Short as possible, they informed her that that her daughter was actually dead.
Sex. Beauty. Violence. The story had it all, and soon made front page news across the nation. "Police seek mad pervert in girl's death," ran one headline in the Washington Post.