Case 1: Investigation of anonymous threats written by two different authors collaborating

In the first section of this report four anonymous letters highly critical of A and B were selected for comparison to determine how many authors were responsible for these communications. Analysis of the format and organization, psycholinguistic and thematic characteristics of these letters led to the conclusion that they were authored by two separate persons collaborating on at least two of the letters. In section two specific characteristics of the two authors were extracted from the anonymous letters for subsequent comparison to likely authors. In section three Mr. C—whose writing samples had format and organizational characteristics in common with the anonymous letters-- was evaluated as a possible author of the notes. But based on thematic and psycholinguistic characteristics, Mr. C was found unlikely to be an author of the anonymous letters.

Next, due to his overlap with many of the derived anonymous author traits, Mr. D was evaluated as a potential author of the anonymous notes to B. Format and organization, thematic, psycholinguistic characteristics and information on Mr. D’s personal involvement in related issues produced strong evidence that he was the author of these communications. In addition, Mr. D’s consistent references to his son allegedly being “attacked” by A paralleled a significant portion of the content of the notes to B. These and other overlapping themes from both Mr. D and the letters supported his authorship of the anonymous notes. Based on the finding that the authors of the anonymous notes were likely male and female collaborators, Mrs. D’s writings were next compared to the writings of anonymous author two. Results from thematic and psycholinguistic analysis, as well as data on her involvement with the organization indicated that Ms. D was the author of anonymous notes two and three addressed to the members. Her specific overlap with the idiosyncratic language used by this author and with the hypothesized characteristics of this writer also supported this contention.