Research Summary In this study, we use a novel application of group‐based trajectory modeling to estimate pathways to prison for a sample of 13,769 first‐time prison inmates in New York State. We found that 12% of the sample was heavily involved in the criminal justice system for 10 years prior to their first imprisonment. We also found that less than one quarter of the sample had little contact with the criminal justice system prior to the arrest that resulted in imprisonment. Policy Implications Slightly less than one quarter of first‐time inmates are not known to the criminal justice system prior to the commitment arrest. For these inmates, crime‐prevention interventions that identify participants through criminal justice processes will not be effective. However, the arrest rates for a substantial portion of the sample over the 10‐year period before imprisonment suggest a staggering number of opportunities for intervention as these individuals churn through the system.