Dr. Gregory Herek is an internationally recognized authority on sexual minority issues, including stigma, prejudice and violence based on sexual orientation. He also has conducted pioneering research on HIV-related stigma. A Professor Emeritus of Psychology at the University of California, Davis, he has published more than 100 scholarly papers and 7 edited volumes on these and related topics, and has worked extensively to communicate the findings of scientific research to legislators, policy makers, and the courts. He has served as an expert witness for numerous legal cases, including Perry v. Schwarzenegger, the successful challenge to California's Proposition 8. He also has assisted the American Psychological Association in preparing more than 20 amicus briefs, including the APA brief cited by the US Supreme Court in its 2015 Obergefell opinion, which established the constitutional right of same-sex couples to marry.