Public trust in journalism is waning, yet research on disinformation has focused predominantly on non-institutional sources such as social media or partisan websites. Far less is known about how deception can emerge within mainstream newswriting that outwardly adheres to professional norms. This study addresses that gap through a corpus-assisted discourse analysis of fabricated and verified reporting by Stephen Glass, a former journalist for The New Republic whose fabrications were exposed in 1998. A purpose-built, matched-author corpus of twenty-three articles (twelve fabricated, eleven verified) was examined using frequency profiling, keyness, collocation, and concordance analysis informed by Appraisal Theory. The analysis identifies systematic linguistic contrasts between fabricated and verified journalism: fabricated texts display lower lexical density, heavier use of verbs and pronouns, and a more personalised narrative style. Evaluative items such as most, just, and not occur more frequently and perform rhetorical functions of emphasis, mitigation, and denial. Collocational and attributional evidence shows that fabricated articles embed stance more often in the journalist’s own voice, projecting confidence and sincerity while limiting alternative readings. By holding author, outlet, and register constant, the study isolates linguistic traces of deception from broader stylistic variation. Methodologically, it demonstrates how corpus tools can be integrated with discourse analysis to reveal how deception is enacted through patterned use of grammatical and evaluative resources. The findings contribute to ongoing work on disinformation by showing that credibility in fabricated journalism is linguistically performed rather than merely asserted, with implications for media literacy and computational detection of deceptive news.