Decoding Crime Through Language

Criminals may conceal their faces, use false identities and communicate through encrypted platforms, but their words can leave behind clues that technology alone may overlook. In the digital age, forensic linguistics is emerging as a valuable investigative tool, helping law enforcement uncover identities, connect anonymous communications and understand criminal networks.

Forensic linguistics applies the scientific study of language to criminal investigations. It examines vocabulary, grammar, spelling, sentence structure, expressions and writing habits. Even seemingly insignificant choices, such as an unusual greeting, a repeated phrase or a distinctive spelling preference, may help investigators establish links between different messages.

Every individual develops linguistic habits shaped by education, geographical background, profession and social environment. Forensic linguists analyse these patterns to determine whether disputed texts may have been written by the same person. Such analysis can help investigate anonymous threats, online harassment, fraud, blackmail and communications linked to organised criminal activities.

One striking example involved Shannon McCoole, who operated a dark-web child abuse forum in the early 2010s. Investigators noticed his repeated use of the unusual greeting “hiyas”. By examining publicly accessible online forums, they identified similar linguistic habits associated with accounts linked to his interests in basketball and vintage vehicles. These clues helped investigators connect an anonymous online identity to a real-world individual, contributing to his identification, arrest and conviction. The investigation subsequently generated intelligence that helped prosecute hundreds of offenders and rescue at least 85 child victims.

Another significant case involved Matthew Falder, who pleaded guilty in 2018 to 137 charges relating to child sexual exploitation, abuse and blackmail. Investigators sought assistance from forensic linguists Tim Grant and Jack Grieve to analyse his online communications. Their examination identified distinctive expressions across different messages and investigated linguistic characteristics that could provide clues about the author. The resulting linguistic profile substantially matched the offender and contributed to the wider investigation leading to his identification and conviction.

Modern forensic linguistics increasingly combines linguistic expertise with computational methods, digital evidence analysis and artificial intelligence. These approaches can help process large collections of messages, identify recurring expressions and detect similarities across online platforms. However, linguistic similarities alone cannot establish guilt. Common expressions may be shared by many individuals, and offenders may deliberately disguise their writing styles. Findings must therefore be corroborated with digital records and other independent evidence.

In India, forensic linguistics could strengthen digital crime investigations by treating language as an investigative clue. Despite its international value, no publicly documented Indian case has confirmed the identification of an anonymous online criminal specifically through linguistic analysis. Integrating forensic linguistics, AI and digital forensics could strengthen investigations, with findings corroborated by independent evidence. In threatening emails, ransom communications and anonymous social media posts, sentence construction, word choice and regional idioms may offer valuable leads. Investigators could explore linguistic profiling across Hindi, English and other languages, particularly when offenders use multiple identities or platforms. Collaboration between forensic linguists, cybercrime units and language-technology researchers could develop India-specific methods to examine not only what messages communicate but also what their linguistic characteristics may reveal about their authors.

As artificial intelligence enables increasingly sophisticated scams, deceptive online interactions and fabricated communications, analysing language is becoming more relevant to modern investigations. Collaboration among forensic linguists, investigators, digital specialists and legal professionals can strengthen investigative intelligence while safeguarding evidentiary standards.

Forensic linguistics reveals that even when criminals hide their identities, their words may preserve traces of who they are. By combining linguistic analysis with corroborative evidence, investigators can transform ordinary conversations into meaningful investigative leads and bring hidden criminal activities closer to the light of justice.

(Kumar is a retired IPS officer and forensic science expert. Das is a research associate at Indian Pharmaceutical Alliance.)