This study aimed to design and evaluate a proactive, school-based educational framework functioning as an early diversion mechanism for vulnerable youth at risk of future justice system involvement. The study addressed the question of whether the presence of structured early identification, individual learning support, and combined behavioral and social-emotional interventions might have led to a decrease in the occurrence of academic disengagement, disciplinary escalation, and criminogenic risk indicators. It adopted a quasi-experimental longitudinal research design where 180 at-risk students (n = 90 intervention; n = 90 control) were used. These groups were tested to be equivalent at the baseline (p > 0.05). The intervention was provided in a 12-month multi-tiered support model that incorporated academic support, behaviour regulation, restorative practices, and involvement of family. Repeated-measures ANOVA, multilevel modeling, multilevel mediation analysis, and thematic qualitative analysis were used to assess the outcomes. There was significant time × group interaction effects on GPA (F (1, 178) = 18.42, p < 0.001) and attendance (F (1, 178) = 21.75, p < 0.001) having large effect sizes (d = 0.82; d = 0.91). There were significant decreases in disciplinary referrals and behavioral risk scores in behavioral outcomes, with intervention attendance being a significant predictor of behavioral risk (β = −14.72, p < 0.001). The risk indicators on justice decreased greatly (t (178) = 5.63, p < 0.001), and the probability of high-risk classification reduced from 62% to 29% of high-risk in the intervention group. The mediation analysis showed a significant indirect effect (−6.45, 95% CI [−9.12, -3.78]) when it comes to academic engagement and self-regulation. For vulnerable adolescents, proactive, composite educational innovations can generate positive academic results and significantly diminish danger in terms of conduct and equity, and place schools as efficient early diversionary frameworks.