The anonymous letter writer--a psychological profile?

Anonymous letters fall into many categories--threats, obscene messages, racial slurs, extortion demands, guilty conscience statements, stool pigeon letters, robbery or burglary notes, and so forth. These are examined by the document examiner for any information that may lead to the identity of the writer. Such examinations involve unusual aspects of paper or envelopes, watermarks, detection of indented impressions, and so on, and also a comparison with previous anonymous submissions. Several cases will be discussed where, additionally, psychological profiles of the writer were produced by a psychiatrist and a psychologist, based upon the content of the letters.