There are several well-documented contemporaneous crimes that share similar themes with the Sweeney Todd legend and could possibly have served as inspiration for Thomas Prest. In December 1784, The Annual Register reported on a barbarous barber near Fleet Street who, in a jealous rage, cut his victim's throat from ear to ear before disappearing into the night.
Read the actual newspaper article.
The Newgate Calendar (or Malefactor's Bloody Register), a five-volume biographical record of notorious criminals housed at Newgate Prison published in the late 1700s, recounted the gruesome story of the renowned (and curiously, similarly named) mass-murderer Sawney Bean, the "Man-Eater of Scotland." Bean was executed along with his entire family for robbing passers-by, then murdering the victims and eating the corpses.
Joseph Fouche, who served as Minister of Police in Paris from 1799 to 1815, graphically documented in his Archives of the Police a series of murders committed in 1800 by a Parisian barber. Fouche wrote that the barber was in league with a neighboring pastry cook, who made pies out of the victims and sold them for human consumption. While there is some speculation about the authenticity of this account, the story was republished in 1824 under the headline "A Terrific Story of the Rue de Le Harpe, Paris" in The Tell Tale, a London magazine. Perhaps Thomas Prest, scouring publications for ideas, read about the Paris case and stored it away for later use.
Or perhaps Prest was inspired by a libel suit in 1818 against scandalmonger James Catnatch. Catnatch regularly published rumors, innuendo, false stories and outrageous headlines to drum up business for his one-page news sheets. One banner declaring "A Number of Human Bodies Found in the Shop of a Pork Butcher" nearly drove Drury Lane butcher Thomas Pizzey out of business. Pizzey filed a libel suit against Catnatch in retaliation, which focused a great deal of attention on the publisher's corrupt catchpenny tricks. Court documents described Catnatch as an "evil, wicked" person with a "malicious mind and disposition." The butcher's good name was ultimately restored when the Clerkenwell Court found the publisher guilty and sentenced him to six months in the House of Correction for his crime.
Read the full account of Sawney Beane's crimes
Newspaper, Novel, Blood