Proprietary software is used throughout the criminal justice system, and the trade secrets of software vendors are regularly deemed more important than the rights of the accused to challenge the results of these complex systems. We will lay out the map of software in this space from DNA testing to facial recognition to estimating someone’s likelihood of committing a future crime. We will detail hurdles that prevent oversight and examples of problems found with third-party review. Adams will demo his findings from reviewing NYC’s FST source code, which was made public by a federal judge after years of the city’s lab fighting disclosure. Greco will provide insight into the wider world of software used in the criminal justice system -from technology that law enforcement admits to using but expects the public to not question to technology that law enforcement denies despite evidence otherwise. Matthews will talk about the wider space of algorithmic accountability and transparency and why even open source software is not enough.