In 2014 we were contacted by the Los Angeles Sheriff’s Department (LASD) Custody Division, and asked to build a DES model that could project their jail population three years into the future. In April, 2015 we reported preliminary projections based on a March 1, 2015 starting date. From there, we worked with LASD to build a more sophisticated model and were able to update it in time in order to make better predictions based on an October 1, 2015 starting date. Not only did our projections improve with the availability of more information on how Proposition 47 affected the jail system, but they were also improved by knowledge we gained from LASD officials.
Our model now includes an algorithm to simulate early release policies and can project the person-day savings realized from this policy. A real benefit to the model is that it can answer any “what-if” policy question, provided that we have the data to do so. In this case, LASD wanted to know what their person-day savings would be over a three year time horizon if they continued with their current early release policy. We were also able to show them what their jail population would look like over three years if they chose to use different early release policies.
Not only can the model answer questions about different policy outcomes, it can also keep separate databases on those affected by the policy. In the case of LASD, a dedicated database was created that contains the descriptive analyses of the inmates released under their early release policy. This database can provide information on the characteristics of the early released inmates, and it can also be used to calculate public safety risks associated with this population. Therefore, proposed adjustments to the early release policy can be evaluated in terms of their impact on the average daily populations, as well as the risk incurred through changes in the size and composition of the resulting early released population.
This ongoing and collaborative project is funded by the Los Angeles County Sheriff’s Department.