The Jack the Ripper corpus contains all the letters or postcards found and transcribed in the Appendix of
Evans S. P., Skinner K. (2001). Jack the Ripper: Letters from Hell. Stroud: Sutton.
The letters were OCR scanned and manually checked. The corpus consists of 209 texts and 17,463 word tokens. The average length of a text in the corpus is of eighty-three tokens (min = 7, max = 648, SD = 67.4).
For more details about the corpus and an authorship analysis of the earliest letters, see