The purposes of this subchapter and subchapter II are—

(1) to support State, tribal, and local programs that prevent juvenile involvement in delinquent behavior;

(2) to assist State, tribal, and local governments in promoting public safety by encouraging accountability for acts of juvenile delinquency;

(3) to assist State, tribal, and local governments in addressing juvenile crime through the provision of technical assistance, research, training, evaluation, and the dissemination of current and relevant information on effective and evidence-based programs and practices for combating juvenile delinquency; and

(4) to support a continuum of evidence-based or promising programs (including delinquency prevention, intervention, mental health, behavioral health and substance abuse treatment, family services, and services for children exposed to violence) that are trauma informed, reflect the science of adolescent development, and are designed to meet the needs of at-risk youth and youth who come into contact with the justice system.