The study focuses on speech patterns typically used in litigation documents issued at the stage of criminal proceeding initiation and pre-trial investigation, which belong to the genre of decree. It is stated that Russian Federation Criminal Procedure Code and most of the Comments to it lack any language requirements to the text organization in these litigation documents. The article is aimed at defining characteristics of the decree genre structure; in particular, lexical and grammatical means that are used in decree texts are equated to the language norms. Some most frequent cases of lexical compatibility violation within set expressions and cliché of litigation documents and their combinations are detected. The author adheres to the opinion that language norms violations may have legal consequences in qualifying offenses and their types. The analysis of syntactic structure of sentences reveals that there is no distinction in the linguistic category of event completeness, in the texts they are presented as hypothetical events. Several aspects of modality in decree texts are studied. The author lays down some requirements on composing a narrative part of the decree as a forensic genre, makes an assertion that it is time to formulate some firm linguistic criteria of decree documentation organization and indicate the consent on expediency of linguistic expertize.