forensic linguistics, cryptanalysis, German criminalistics, coded communication, authorship attribution, linguistic forensics 1. Introduction The intersection of language and law has long been a site of intellectual inquiry, but only in the last half-century has forensic linguistics emerged as a systematic, evidence-based discipline. Within this field, most attention has been given to authorship identification, plagiarism detection, and speaker profiling. However, a specialized subdomain—forensic cryptanalysis of human-generated codes—has remained underexplored. Klaus Teltenkötter stands as a rare figure who bridged academic linguistics, practical cryptography, and police investigative work.
| Type | Description | Example | |------|-------------|---------| | | Replacing letters with other letters, numbers, or symbols | A=1, B=2 | | Homophonic substitution | Multiple symbols for same letter to mask frequency | E = 3, 17, 42 | | Transposition | Rearranging letter order | Reverse writing | | Semiotic codes | Symbol systems with cultural meanings | Runes, alchemical signs | | Jargon codes | In-group slang or argot | Prisoner cant | | Visual camouflage | Hiding text within images or patterns | Microscript in drawings | klaus teltenkötter
During the late 1970s, he became fascinated by the Geheimschriften (secret scripts) used by German youth movements and prisoner subcultures. He collected over 200 distinct code systems, many of which were undocumented in academic literature. This personal archive would later form the basis of his forensic reference collection. In 1985, Teltenkötter was approached by the Düsseldorf police to analyze a series of handwritten threatening letters where the writer had replaced certain letters with astrological symbols. His successful decryption led to a confession. By 1988, he was officially recognized as a gerichtlich vereidigter Sachverständiger (court-sworn expert) for “coded writings, secret scripts, and linguistic disguise.” He collected over 200 distinct code systems, many