Trajectories of criminal justice involvement among a state mental health agency's clientele: Findings from a 10-Year cohort study

Understanding temporal patterns in the behavior of public mental health systems' clientele is crucial to formulating policy and planning services. An important domain in this regard is involvement with the criminal justice system. This presentation describes the application of “trajectory analysis,” a methodology typically used to identify age-related patterns of offending over time in a developmental framework, to the analysis of temporal patterns of criminal justice involvement among a group of mental health service consumers. The study uses data on a statewide cohort of individuals aged 18-64 receiving services (case management, residential programming and/or inpatient services) from the Massachusetts Department of Mental Health in 1991 and whose arrests were followed for roughly 10 years (N=13,876). Using the zero-inflated Poisson trajectory analysis methodology with a cohort subsample that included persons with two or more arrests over the ten year period, five trajectories of criminal justice involvement were identified. Comparison of the five groups defined by these trajectories revealed substantial between-group differences with regard to members' demographic characteristics and offense types. The implications of these findings for understanding criminal justice involvement in this population and the use of the methodology for developing services at the interface of the mental health and criminal justice system are discussed.