In recent years, over two hundred men and women born or raised in the West have participated in, or provided support for Islamic terrorist plots and attacks. Several studies have examined the demographics of homegrown Islamic terrorists: their socioeconomic status, education level, professional prospects, and possible mental illnesses. To date, no study has empirically examined the process through which these terrorists are radicalizing, which constitutes a substantial gap in the literature. This study seeks to address that gap through an empirical examination of 117 homegrown "jihadist" terrorists from the U.S. and U.K.About the Author: Daveed Gartenstein-Ross is the Vice President of Research at the Foundation for Defense of Democracies (FDD), and the director of its Center for Terrorism Research. He is the author of My Year Inside Radical Islam (Tarcher/Penguin, 2007), which details his time working for the head U.S. office of the Al Haramain Islamic Foundation, an international Wahhabi charity that the U.S. Treasury Department has named a specially designated global terrorist entity. Gartenstein-Ross is a Ph.D. candidate in world politics at the Catholic University of America, and earned a J.D. from the New York University School of Law. Laura Grossman is a Research Analyst at the Center for Terrorism Research. She received a bachelor's degree in history from the University of Michigan, and a M.S. in global affairs from New York University. At NYU, she was a founding member and managing editor of Perspectives on Global Issues, the first student-run publication at NYU's Center for Global Affairs.