Dr. Yerke received his Doctorate in Clinical Psychology (Psy.D.) from the California School of Professional Psychology at Alliant International University in San Francisco. As a licensed psychologist, he has provided individual and group psychotherapy, as well as performed psychological and forensic assessments. He has spent considerable time working with clients dealing with substance abuse and dependence issues, chronic mental illnesses, and criminal behaviors. He specializes in issues related to gender and sexuality. In the field of forensic psychology, he has focused on assessing and treating sexual offenders, as well as supervising doctoral students working with this population. His research has focused on the transgender community, and he has presented and published materials related to this population.