From August to November 1888, the Central News Agency and Whitechapel Vigilance Committee received hundreds of letter from authors claiming the identity of Jack the Ripper. Most were considered a hoax, and some believe letters were created and sent by journalists searching for a good story. Of these, there are three considered to be written by the hand of the true Jack the Ripper.
The first of the letters was sent to the Central News Agency on September 27, 1888. Its consideration as evidence comes from the content of the letter, which included information on clipping the earlobe of future victims. Days later, Catherine Eddowes was found with parts of her ear cut off. Afterward, the letter was released and published to newspapers with the hope of any person recognizing the handwriting. This was also the first reference to the Whitechapel killer as "Jack the Ripper."
The "Saucy Jacky" postcard was sent to the Central News Agency on October 1, 1888. The card's handwriting resembled "Dear Boss" and also foretold a double event. This event was made clear after the double murders of Elizabeth Stride and Catherine Eddowes. The information was disclosed in the letter before being released to the public, causing the postcard to be considered credible.
Received by George Lusk, head of the Whitechapel Vigilance Committee, on October 16, 1888, "From Hell" did not match the handwriting of the two previous letters, but was sent along with a package. The contents of the box was half a kidney determined to belong to victim Catherine Eddowes due to a missing kidney at the scene of the crime. Medical examinations following the crime were inconclusive as to whether or not the kidney was that of Eddowes. Evidence supporting that the kidney was Eddowes' found both the kidney remaining intact and the kidney sent to Lusk were in the same stage of Bright's Disease.
"The Juwes are not the men That Will be Blamed for nothing." This inscription, along with a blood-stained apron were found on the night of the murders of Stride and Eddowes.