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SIGMA – Behavioral Threat Assessment (BTA) EXPERTS

An Elite Team on Your Side

school safety
Exclusively through Raptor, schools have direct access to SIGMA, an industry-leading collective of behavioral threat assessment experts with more than 250 years of experience and expertise in assessing and managing threats and other troubling behaviors in K-12 schools, higher education, and workplaces.

Experience

SIGMA experts have threat assessment experience through careers in federal, state, and local law enforcement, education, criminal justice, mental health, and the law. SIGMA's expertise comes from direct experience assessing thousands of threat cases.

Expertise

Work of SIGMA's experts is referenced throughout several U.S. national standards and federal guides, which are regarded as best practices in BTA and threat management.

Practice

SIGMA experts have trained and coached thousands of school, law enforcement, and mental health professionals in BTA best practices. SIGMA's team has provided expert guidance on thousands of cases to help eliminate school violence.

Meet the SIGMA Team

Picture of Marisa R. Randazzo, PhD <br> Executive Director of Threat Assessment

Marisa R. Randazzo, PhD
Executive Director of Threat Assessment

Dr. Marisa Randazzo is an international expert on threat assessment with over 25 years of experience. She co-directed the landmark Safe School Initiative conducted jointly by the U.S. Secret Service and the U.S. Department of Education. Dr. Randazzo has served as Chief Research Psychologist for the U.S. Secret Service and is a co-author of several leading books on the topic. She has worked with thousands of K-12 schools, higher education institutions, and workplaces across the country in developing and training their BTA teams and consulting on thousands of cases worldwide.  

Picture of David Okada, CTM  <br> Senior Threat Manager

David Okada, CTM
Senior Threat Manager

Lt. Dave Okada is a seasoned national expert in threat assessment and management, including more than 20 years of specialized experience in the field and an extensive 33-year career in law enforcement. He is the co-author of "Assessing Student Threats: Implementing the Salem-Keizer System" and other essential investigative guides, which serve as vital resources for effective threat management. Dave currently serves as the National President of the Association of Threat Assessment Professionals (ATAP) and has previously held other board positions as well.  

Picture of Melissa Reeves, PhD, NCSP, LPC  <br> Senior Threat Manager

Melissa Reeves, PhD, NCSP, LPC
Senior Threat Manager

Dr. Melissa Reeves is a nationally certified school psychologist, licensed special education teacher, licensed professional counselor, and former district coordinator of social/emotional/behavioral services. She recently served as President of the National Association of School Psychologists and is co-author of the NASP PREPaRE School Crisis Prevention and Intervention curriculum.

Picture of Lea Bauer, M.Ed., CFE <br> Senior Threat Manager

Lea Bauer, M.Ed., CFE
Senior Threat Manager

Lea Bauer is a former Senior Special Agent of the U.S. Secret Service bringing over 20 years of experience in threat assessment, protective operations, and physical security. Ms. Bauer has worked directly with the Department of Defense to develop and conduct training on threats from Islamic extremists; recruitment and radicalization; terrorist financing; and interviewing techniques. Lea brings vast experience in behavior threat assessment and management through training and case expertise across hundreds of K-12 schools and higher education institutions.

Picture of Stephanie Stein Leite, Psy.D.   <br> Senior Threat Manager

Stephanie Stein Leite, Psy.D.
Senior Threat Manager

Dr. Leite is a psychologist who has worked with high-risk children, adolescents and adults for over 25 years, focusing on the prevention of violence. She is the recent past president of the New England Chapter of the Association of Threat Assessment Professionals (ATAP) and is a peer reviewer for the Journal of Threat Assessment and Management.

Picture of Jeffrey W. Pollard, PhD, ABPP <br> Senior Threat Manager

Jeffrey W. Pollard, PhD, ABPP
Senior Threat Manager

Dr. Jeff Pollard is a founding member of George Mason University’s Threat Assessment Team, where he is an Adjunct Faculty in the Department of Criminology, Law and Society teaching threat assessment. He also serves as the Behavioral Science Advisor to Mason’s Police Department. Dr. Pollard has over 30 years of experience consulting on threat assessment to universities, colleges, private individuals, and government agencies throughout the country.

Picture of Christopher Wren <br> Senior Threat Manager

Christopher Wren
Senior Threat Manager

Christopher Wren has diverse and extensive work experience in threat assessment and law enforcement. He is currently the President of the Desert Southwest Chapter of the Association of Threat Assessment Professionals (ATAP). Previously, he has served as President of the Arizona Chapter from 2014-2018 and the National LE Scholarship Chair. Christopher has served as a Program Manager for the Arizona Counter Terrorism & Information Center and as a Detective and Senior AZ-Statewide Threat Liaison Officer for the City of Phoenix Police Department.

Picture of William J. Zimmerman, CTM  <br> Senior Threat Manager

William J. Zimmerman, CTM
Senior Threat Manager

Bill Zimmerman is one of the world’s first Certified Threat Managers (CTM). A 32-year veteran of the U.S. Capitol Police, Detective Zimmerman was responsible for investigating threats against Members of the U.S. Congress, their families, and other statutory protectees. He regularly reviewed, evaluated, and intervened with persons who threatened or engaged in inappropriate contact with Members of Congress. Bill currently serves as the National Second Vice President of the Association of Threat Assessment Professionals (ATAP). Previously, he was the President of the DC Mid-Atlantic Chapter of ATAP. Mr. Zimmerman has worked with hundreds of K-12 Schools and Higher Education institutions in training and consulting on Behavior Threat Assessment cases.  

Picture of Flavia Lopes, MA  <br> Program Manager

Flavia Lopes, MA
Program Manager

Flavia Lopes currently serves as Program Manager for SIGMA Threat Assessment Services at Raptor. Flavia holds a masters degree in special education and curriculum and instruction. She also holds an educational endorsement in English as a Second Language (ESL). Previously, Flavia worked as a Special Education teacher for 5 years in a K-5 elementary school. She has worked with students of varying disabilities, needs, and ages. More recently she held an Accountability Specialist position within an elementary school working to ensure compliance surrounding special education.

Picture of Denise Wolf, MA  <br> Organizational Dynamics Specialist

Denise Wolf, MA
Organizational Dynamics Specialist

Denise Wolf is the Organizational Dynamics Specialist with the SIGMA team at Raptor. Denise has a B.A. in Communications and Psychology, and an M.A. in Psychology. Her expertise includes leadership coaching, process development and integration, organizational strategy consulting and change management. She has worked with a variety of companies in a number of industries, ranging from high-tech to multi-unit retail and distribution. Her broad experience in different aspects of business gives her the ability to identify big picture issues and to work with various levels of the organizations to solve them. She helps organizations identify their vision, develop clear goals to achieve defined objectives, and establish systems that foster open communication and the exchange of ideas. Denise also provides expertise to assimilate information from various groups to assist clients in adjusting actions to meet the evolving needs of both the internal and external environments. Denise has worked with several companies during their high growth phases. She has been a part of training and implementing new programs. As a LMHC, Denise specializes in helping others understand and move through the impact of systemic, intergenerational, and family trauma.