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In recent decades, social scientists have created a treasure trove of empirical and sociological data that defenders can and should use to help their clients. Evidence rules, criminal law, and criminal procedure are filled with concepts informed by social science. When is evidence likely to unfairly prejudice a defendant in the eyes of a jury? Do police interact differently with members of minority populations and how should that inform concepts of reasonableness? How easy or difficult is it for people to identify individuals they see during high-stress criminal episodes? How effective are police interrogation tactics at getting at the truth versus getting suspects to say whatever the interrogator wants to hear?

Courts have also shown more willingness in recent years to incorporate social science data into their decisionmaking on criminal justice issues. Perhaps the most prominent example is in juvenile adjudications. Studies on juvenile brain development were an integral part of the Supreme Court's decision in Miller v. Alabama' banning automatic life without parole for juveniles as cruel and unusual under the Eighth Amendment. Lower courts have also relied on social science data to inform the role that a suspect's race should play in Fourth Amendment inquiries. For example, in Commonwealth v. Warren, the Massachusetts high court relied on data about racial profiling in Boston to discount the relevance of a suspect's flight in the Fourth Amendment analysis of whether there was sufficient reasonable suspicion to stop. More recently, the Ninth Circuit Court of Appeals agreed that social science data about racial profiling in Seattle should similarly "inform the inferences to be drawn from an individual who decides to step away, run, or flee from police without a clear reason to do otherwise". And many lower courts have considered social science research when making decisions about whether to admit forensic science, eyewitness identifications, and confessions.

These are just a few of the many possible ways that defense attorneys can leverage social science to help their clients. So how does a defense attorney find and harness this data to help clients? And what are the evidentiary and legal tools that defense lawyers can use to incorporate social science into their practice? There are a number of ways to learn about relevant social science research. The National Academy of Sciences, Rand Corporation, Sentencing Project, and Pew Research Center have websites where they collect and publish reports relevant to criminal law and criminal justice. And many legal scholars are now writing law review articles, blogging, or posting social science research on social media. Just as defense attorneys search for precedent when thinking about how to craft their legal arguments, so too should they search for helpful social science.