<p>This study explores the indirect effects of rumination and mobile phone addiction on the relationship between stress and aggressiveness, as well as the moderating role of gender in the associations between mobile phone addiction and aggressiveness, and rumination and aggressiveness. On November 10, 2023, February 7, 2024, and May 12, 2024, we conducted three waves of longitudinal data collection using the Stress Questionnaire, Rumination Questionnaire, Mobile Phone Addiction Index Questionnaire, and Aggressiveness Questionnaire with 536 community correctional personnel. Structural equation modeling was employed to examine the relationships among stress, rumination, mobile phone addiction, and aggressiveness. Stress significantly and directly predicted aggressiveness. Additionally, stress indirectly predicted aggressiveness through the independent mediating effects of rumination and mobile phone addiction, as well as through the sequential mediating effect of rumination and mobile phone addiction. The moderating effects of gender on the relationships between mobile phone addiction and aggressiveness, and rumination and aggressiveness were not significant. Stress can significantly predict aggressiveness both directly and indirectly. Individuals experiencing rumination may feel physically and mentally exhausted, leading them to seek escapism or entertainment, which over time can develop into behavioral addiction—a phenomenon we refer to as “rumination addiction.” Society should pay greater attention to the assessment of stress and aggressiveness in community correctional personnel. Early screening can help authorities provide effective psychological interventions and treatments for this special population, preventing them from committing further violent offenses due to mental health issues.</p>