Measuring Authorship - A Tribute to Forensic Discourse Analysis

It is believed by many that our fingerprints are as unique as our DNA. Owing to the advances in modern technology and the aid of computers, it is possible to use software that is able to measure all the probabilities of occurrence of identical fingerprints, DNA, written or spoken discourse. In recent years, forensic discourse analysis experts and linguists have been trying to measure the degree to which every individual is unique. These findings are especially relevant for analysing the content of suicide letters, testimonies, testaments, ransom demands, confessions, SMS messages, diary entries etc. The quest of forensic discourse analysis is to apply the linguistic knowledge to the legal context with the aim of deciding on the authorship of the above-mentioned short notes. In applying the linguistic knowledge to the analysis of suicide letters, for instance, it is of great importance to determine whether there is a murder behind such a letter, viz. whether the letter is a genuine suicide letter. Another interesting phenomenon is related to testimonies, viz. the degree to which the interrogators added written content to the oral confession, or the degree to which the testimony, based on the linguistic evidence, is false. In this process, experts apply various methods of measuring the degree to which the testimonies are authentic. Some of these methods involve measuring sentence length average, word length average, collocations analysis, and forensic transcription. The aim of this paper is to pay tribute to forensic discourse analysis of English texts and focus on some of its methods that are particularly related to the application of the linguistic knowledge. In doing so, we shall focus on a brief analysis of two well-known cases, Derek Bentley and Susan Smith.