Jack the Ripper: Case Study

Lesson 7: Using Forensic Evidence to Investigate an Old Crime

Fingerprints and Watermarks

The stationary used on some of the Ripper letters had a watermark from Perry & Sons. This watermark was also found on some of Sickert's personal correspondence. On the "Openshaw" letter, both traces of mitochondrial DNA and the same watermark Sickert used in his personal correspondence were present.

Cornwell's Case against Walter Sickert-The Ripper Letters

Even though the outcome of the forensic examination was disappointing, the fact that the same watermark appeared on some Ripper correspondence and on Sickert's personal correspondence is pretty strong circumstantial evidence.

Cornwell personally believes that most of the Ripper letters are authentic and the handwriting is disguised in some of the ones that don't appear to be written by the same person. She also believes that the Ripper disguised the language in the letters in an attempt to appear more ignorant than he actually was, for some of the words are not words a semi-literate person would use or even know.

Also interspersed within the Ripper letters are several phrases that could be associated with Walter Sickert. She believes the words "ha ha" that appear quite often in the Ripper letters may stem from Sickert's mimicking James Whistler's annoying laugh. Some of the Ripper letters are also signed "Mr. Nemo", which was Sickert's stage name from his acting days. Mr. Nemo, however, was also a common phrase around the time and had the same meaning as signing a letter "Anonymous."

Experts Disagree about the Connection between the Ripper Letters and Sickert's Guilt

Experts argue that the Openshaw letter is not one of the three Ripper letters generally believed to be an authentic Ripper letter, which has long been considered a hoax. In fact, most of the Ripper letters are considered fakes. So many bogus Ripper letters were received by the police - over 600, postmarked around the world - that writing them appeared to have become quite a fad. If Sickert did pen one Ripper letter, that did not necessarily prove he was Jack the Ripper, but one of hundreds of hoaxers.

If taken before a court of law today, it could be argued that Sickert wrote the letter as a hoax, or someone else used his stationary. The similar watermark could also be coincidence as there were few paper mills in operation at that time, and the stationary was in common use by a great number of people besides Walter Sickert. The same watermark did not mean that the paper came from the same batch.

The Sickert Paintings

In the course of her investigation, Cornwell also purchased thirty of Sickert's paintings to look for DNA evidence and fingerprints. The paintings Cornwell purchased were torn apart and the frames and canvas checked for fingerprints, blood, or other evidence. None was found. The case could not be solved through either DNA or fingerprint evidence.