Dr. Mahlon, Juma2025-02-182025-02-182024-12-102454-6186https://irepository.aua.ac.ke/items/bf054452-c23a-428c-a15f-d05fefdebc55Full Text ArticleGrit – defined as perseverance and passion for long-term goals has been considered a prognosticator and requisite trait of success and achievement and has been utilizing the domain-general Grit-S - for its good internal consistency, and test-retest stability. The domain-specific aspects of grit are required and a valid tool has been an imperative need. This quantitative study introduced the Prison Grit Scale (P-GS) to recidivists (N =418) selected through purposive and systematic random sampling to ascertain the reliability and validity using the partial least squares structural equation modeling. The results demonstrate that P-GS possesses good psychometric properties. The factor loadings of courage, conscientiousness, excellence, resilience, and optimism were between 0.754 - 0.836, thus acceptable. P-GS’s composite reliability of 0.895 is acceptable; a value greater than the recommended 0.70, and the rho-a value of 0.857 falls between Cronbach’s Alpha (0.853) and composite reliability (0.895). The convergent validity’s average variance extract was 0.631; above the accepted threshold of 0.50. Lastly, discriminant validity using Fornell and Larcker indicator loadings scored 0.794 and fell between 0.65 and 0.85. The conclusion is that P-GS has good internal reliability and convergent and discriminant validity. This implies the support of domain-specific aspects of grit and can benefit positive psychology researchers in the criminal justice system. A convergent parallel design in a mixed method is recommended for future research, utilizing more women respondentsen-USRecidivismGrit scale developmentGritPrisonerArticle