Brian Levin is director of the Center for the Study of Hate & Extremism, a nonpartisan research and policy center at California State University, San Bernardino. Levin is also a professor of criminal justice at the university.

Gregory M. Herek is a psychologist at the University of California, Davis. He is a well-known scholar in the areas of prejudice against lesbians and gay men, hate crimes and anti-gay violence, and AIDS-related stigma.

Repent America is a Philadelphia-based evangelistic organization that works against homosexuality, abortion and evolution.

Janet Porter is the president and founder of Faith2Action, a Christian advocacy group that works to influence politics and legislation. The group is based in Dania Beach, Fla.

The International Association of Chiefs of Police is a professional organization of law enforcement personnel that works to confront new challenges in policing and promote member success. Contact Sarah Guy, the manager of legislative and media affairs.

The Vera Institute of Justice works to improve justice services and systems through research and projects. Nicholas Turner is the president and director.

The Southern Poverty Law Center is a civil rights legal advocacy group based in Montgomery, Ala. Email through the website.

Partners Against Hate works to educate young people about hate and hate crimes. It is based in Washington, D.C. Contact 202-452-8310.