Why was Elizabeth Short's murder called The Black Dahlia murder?

Yes, murder victim Elizabeth Short was called the Black Dahlia. This name caught on because at the same time that her murder was being reported in the newspapers, the movie "The Blue Dahlia", starring Veronica Lake and Alan Ladd was just released and the title displayed in huge letters on movie marquees. Photos of Elizabeth Short that showed her black hair and dressed in black dresses made the connection, the name seemed to suit her and stuck.