Forensic Psychology.
Expert Testimony.
Decisional Clarity.
ABOUT
Dr. Marcus Van Sickle
Dual Board-Certified Forensic Psychologist with experience in federal, military, and civilian criminal and civil courts.
A retired military veteran with 24+ years of service.
Expertise in conducting complex psychological evaluations, providing expert consultation and testimony, and supporting behavioral threat assessment and management operations.
Competency to Stand Trial
Criminal Responsibility
Risk & Threat Assessment
Specialized Expert Testimony
Credentials & Training
Board Certified in Forensic Psychology (ABPP)
Board Certified in Behavioral & Cognitive Psychology (ABPP)
Certified Threat Manager (CTM), Association of Threat Assessment Professionals
MS and PhD in Clinical Psychology
Postdoctoral Master of Science in Clinical Psychopharmacology (MSCP)
Licensure & Scope
Licensed Psychologist (multiple jurisdictions)
Advanced Practice Medical Psychologist (MPAP) in jurisdictions where authorized by law
Areas of Expertise
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Criminal Forensic Evaluations & Expert Testimony
Dr. Marcus R. VanSickle provides comprehensive criminal forensic psychological evaluations and expert testimony in state, federal, and military jurisdictions. His work is grounded in evidence-based forensic methodology, adherence to APA Forensic Practice Guidelines, and extensive experience with complex and high-risk cases.
With dual board certification in Forensic Psychology and Behavioral & Cognitive Psychology and expertise in Clinical Psychopharmacology, Dr. VanSickle brings a broad range clinical and legal expertise to every evaluation. His history as 24+ year military veteran and former Navy Forensic Psychologist provides the cultural competence needed to work with military and veteran populations.
Competency to Stand Trial (CST)Criminal Responsibility / Insanity Evaluations
Mental State at the Time of the Offense
Violence & Risk Assessments
Sentencing Mitigation and Aggravation
Fitness for Duty in criminal matters
Case consultation and expert testimony
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Civil Forensic & Litigation Support
Dr. Marcus R. VanSickle offers comprehensive civil forensic evaluations and litigation support services for attorneys, courts, and organizations. His work addresses complex psychological questions related to damages, capacity, risk, and functional impairment in civil legal matters.
Each evaluation is conducted using evidence-based forensic methodology, objective analysis, and adherence to professional forensic standards.
Psychological injury and emotional distress evaluations
Independent psychological examinations (IMEs)
Capacity evaluations (financial, testamentary, guardianship, decision-making)
Fitness for duty and employment-related assessments
Civil risk and dangerousness evaluations
Record reviews and rebuttal evaluations
Expert testimony
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Behavioral Threat Assessment & Risk Management
Dr. Marcus R. VanSickle provides specialized behavioral threat assessment and management services to organizations, legal professionals, schools, and government agencies. His work focuses on early identification, structured risk evaluation, and practical management strategies designed to reduce the likelihood of targeted violence.
Dr. VanSickle is a Certified Threat Manager (CTM) through the Association of Threat Assessment Professionals and has extensive experience working in high-risk environments and complex forensic cases.
Targeted violence risk assessmentsWorkplace threat evaluations
Student and school threat assessments
Stalking, fixation, and grievance-based behavior evaluations
Pathway-to-violence analysis
Structured risk formulation and management planning
Ongoing consultation and monitoring strategies
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Training, Consultation & Professional Education
Dr. Marcus R. VanSickle provides customized training programs and professional consultation for attorneys, prosecutors, law enforcement agencies, corporations, healthcare systems, and educational institutions.
Drawing from extensive forensic, military, and federal experience, trainings are practical, evidence-based, and tailored to the specific needs of each organization.
Suicide prevention and resilience in high-stress professions
Vicarious trauma and occupational wellness
Behavioral threat assessment fundamentals
Violence risk indicators and intervention strategies
Forensic interviewing principles
Mental health issues in criminal justice settings
High-risk offender management
Why Retain Dr. Van Sickle
Dr. Marcus R. Van Sickle is retained in cases requiring clear, defensible forensic opinions, particularly where cognitive, behavioral, medical, and situational factors intersect.
Attorneys and courts rely on Dr. Van Sickle for his ability to:
Translate complex psychological and neurobehavioral findings into clear, legally relevant opinions
Address competency and criminal responsibility questions grounded in current forensic science and legal standards
Analyze legal relevance of alcohol, memory, sleep, and altered states with precision and scientific rigor
Explain counterintuitive victim behavior without speculation or advocacy
Provide measured, cross-examination-resistant testimony focused on the ultimate legal questions
