Ruth Shefner is a doctoral student in Sociomedical Sciences at the Mailman School of Public Health, on the sociology track. She is also a predoctoral fellow in a NIDA funded T32 on HIV, Substance Use, and the Criminal Justice System. Her work uses mixed methods to study the public health harms of criminalization along the criminal legal system continuum, with specific interests in policing, criminal laws as structural determinants of health, collateral consequences of mass incarceration, and harm reduction in criminal legal settings. Prior to coming to Columbia, Ruth was the Director of the Goldring Reentry Initiative, a program housed at the University of Pennsylvania’s School of Social Policy and Practice that supports individuals pre- and post-release from Philadelphia’s county jail system. She completed her Master of Social Work and Master of Public Health at the University of Pennsylvania, and her Bachelors of Arts in Public Health at Brown University.