Paul Collins in Slate:
In the summer of 1897, that question meant just one thing in Manhattan newsrooms, and it wasn't a request to meet the managing editor. The head everyone sought was of William Guldensuppe, a masseur who had disappeared in late June from his Hell's Kitchen apartment. He'd reappeared scattered in pieces along the Lower East Side, the Bronx, and Brooklyn. What was still missing, though, was his head—which, rumor had it, a jealous lover had hidden inside a block of plaster.
To William Randolph Hearst, the crime was perfect opportunity to trumpet his newly launched New York Evening Journal. Hearst offered a whopping $1,000 reward to solve the crime, and even formed a “Murder Squad” of reporters who were ready to resort to flashing badges and pistols to make citizen's arrests. Yet his stunts were merely improvements on the carnivalesque populism of rival publisher Joseph Pulitzer. Featuring celebrity news and scandal, Pulitzer's New York World had also created the world's first color comic section, and the popularity of strips like “The Yellow Kid” inspired competitors to scoff that the World and Journal were selling comic-strip journalism—”Yellow Journalism,” they called it.
Not to be upstaged by Hearst's Journal, the World stole evidence from the Guldensuppe murder scene by shaving off a piece of a floorboard, testing it, and proclaiming BLOOD IN THE HOUSE OF MYSTERY. They also hired divers to search the East River for Guldensuppe's head. But after a World diving crew was spotted surreptitiously drawing a slimy white mass out of the river, the delicate matter of legality arose. The New York Herald believed the World had the scoop of the day—literally scooping William Guldensuppe's head off the bottom of the East River—and that Pulitzer's henchmen were now concealing the ghastly thing in their editorial offices. In a burst of righteous indignation, the Herald called in the police.
More here.