We are a team of researchers working on a 3-year project to examine the impact of justice reinvestment, defelonization, and Ballot Measure 110 (M110) on the criminal justice system and public safety in Oregon. We are specifically studying the impacts of these possession of controlled substance (PCS) law changes on: (1) law enforcement discretion, (2) prosecutorial decision-making, (3) courts/sentencing, and (4) public safety. To do this, we use a mixed method approach; relying on secondary statewide data (e.g., arrests trends and crime rates), supplemented by interviews with practitioners (e.g., law enforcement officers and prosecutors). This project is supported by the National Institute of Justice.