Forensic psychology expert witness: rigorous psychological evaluation, translated into clear, defensible opinions.
Dr. Andrew Mendonsa is a clinical and forensic psychologist with more than twenty years of practice across private practice, correctional systems, public behavioral health, academia, and regulatory oversight. He serves plaintiff, defense, and court-appointed retentions as a Qualified Medical Evaluator, Agreed Medical Evaluator, and independent examiner — and as an Expert Reviewer for the California Board of Psychology.
A forensic psychology expert witness who still evaluates, still teaches, and still reviews for the state board.
Dr. Mendonsa holds a Psy.D. in Clinical Psychology from the California School of Professional Psychology and an MBA from Texas A&M University, with postdoctoral fellowship and residency training at UC Davis. He is licensed to practice in thirteen states and is a California DWC Qualified Medical Evaluator.
His work sits at the point where clinical psychology meets the legal system: psychological injury and trauma evaluation, suicidology and risk assessment, competency and criminal responsibility, fitness for duty, and the standard-of-care questions that arise when a mental health provider or health plan is the defendant. He is an Expert Reviewer for the California Board of Psychology Enforcement Unit, opining on standards of care, ethics, and alleged professional misconduct — and he spent six years auditing health plans for the California Department of Managed Health Care under the Knox-Keene Act, MHPAEA, and SB 855.
Because he continues to evaluate patients, teach doctoral students, and review cases for the licensing board, his opinions reflect the working standard of care rather than a retrospective or purely academic view. His current caseload runs approximately 60% defense and 40% plaintiff or applicant.
- Current Practice
- Clinical & Forensic Psychologist and Consultant, 2009–present
- Faculty
- Professor of Clinical Practice, University of the Pacific; California School of Professional Psychology
- Board Service
- Expert Reviewer, California Board of Psychology Enforcement Unit
- Certification
- California DWC Qualified Medical Evaluator #150731 (exp. 07/2027)
- Doctorate
- Psy.D., Clinical Psychology — California School of Professional Psychology (APA accredited)
- Postdoctoral
- Fellowship and residency, UC Davis (APPIC accredited)
The evaluations attorneys, carriers, and courts retain him to perform.
Dr. Mendonsa conducts each evaluation below personally — the examination, the testing, and the report. Retentions are accepted from plaintiff and applicant counsel, defense counsel and carriers, employers and agencies, and by court appointment, and are contracted through Expert Witness Networks, Corp.
Qualified Medical Evaluator (QME)
California workers’ compensation psychological med-legal evaluation as a DWC-certified QME (#150731), including causation, apportionment, impairment rating, and Almaraz-Guzman analysis.
Read more →02Agreed Medical Evaluator (AME)
Service as the jointly selected evaluator when applicant and defense counsel agree on a single psychological examiner, with a report written to be relied on by both sides.
Read more →03Independent Medical Examination (IME)
Independent psychological examination for insurers, employers, agencies, and counsel in disability, personal injury, and employment matters — including rebuttal IMEs of an opposing examiner’s findings.
Read more →04VA Nexus Letters & C&P Review
Compensation and Pension examinations and service-connection evaluations for veterans pursuing disability benefits and appeals, including nexus opinions on PTSD, MST, and trauma-related claims, and review of a prior C&P examiner’s report.
Read more →05Competency & Criminal Responsibility
Competency to stand trial (Penal Code §§1368/1370), criminal responsibility and insanity (Penal Code §1026), mental health diversion, mentally disordered offender, and juvenile forensic assessment.
Read more →06Violence, Suicide & Sexual-Risk Assessment
Structured risk assessment for violence, self-harm, and sexual reoffense using validated actuarial and structured professional judgment instruments, and psychological autopsy in completed-suicide matters.
Read more →Where psychological evidence decides the case.
Dr. Mendonsa’s casework spans civil, criminal, administrative, and workers’ compensation matters in superior and federal courts. The subject areas below are the ones that most often turn on psychological proof:
Psychological injury & trauma claims
PTSD, anxiety, depression, and cognitive complaints following injury, assault, or workplace exposure — causation, apportionment, impairment, and future care.
Suicide and psychological autopsy
High-liability review of completed suicides in custodial, inpatient, and outpatient settings: foreseeability, risk assessment adequacy, and deviation from the standard of care.
Fitness for duty & public safety screening
Law enforcement, fire, corrections, and security-sensitive roles — pre-employment psychological screening and post-incident fitness-for-duty determinations.
Licensing board & professional discipline
Standard-of-care, ethics, boundary, documentation, and impairment questions in matters before the Board of Psychology and sister licensing boards.
Insurance denial & medical necessity
Mental health and substance use denial review, medical-necessity opinions, and parity analysis under the Knox-Keene Act, MHPAEA, and California SB 855.
Disability, ADA, FEHA & FMLA
Functional impairment and accommodation evaluations, return-to-work planning, and independent review of disputed disability and leave claims.
Record & Case Review
Review of clinical records, prior evaluations, testing data, and deposition testimony, with a written assessment of what the record does and does not support.
Comprehensive Evaluation
In-person or remote psychological examination with standardized testing, collateral review, and a report written to survive cross-examination.
Rebuttal & Expert Critique
Analysis of an opposing expert’s methodology, instrument selection, scoring, and inferential leaps — including validity and effort testing that was or was not administered.
Deposition & Trial Testimony
Testimony in superior and federal court and in administrative proceedings, with deposition preparation and trial consultation for retaining counsel.
Every area, with the rules that govern it.
Each page below sets out the controlling standard for that kind of case — the statute, the rule, or the evidentiary test — and what a defensible psychological opinion has to establish under it.
Twenty years across practice, corrections, public health, academia, and regulation.
An unusually broad base for a forensic psychologist: direct clinical practice, statewide correctional leadership, health-plan regulatory oversight, doctoral teaching, and licensing-board enforcement review.
Clinical & Forensic Psychologist / Consultant
Private forensic and clinical practice. Expert witness in civil, administrative, and criminal matters in superior and federal courts; QME, AME, and independent evaluator; Expert Reviewer for the California Board of Psychology Enforcement Division.
University of the Pacific — Stockton, CA
Professor of Clinical Practice. Dual appointment teaching in graduate and undergraduate programs; forensic psychology, psychological assessment, law and ethics, and clinical supervision.
California School of Professional Psychology
Clinical Professor. Doctoral instruction, dissertation committee chair, and competency-based curriculum design aligned with APA accreditation standards.
County of Sacramento
Division Chief / Health Program Manager, Primary Health Division. Executive leadership across medical, behavioral health, and integrated wellness programs; annual budgets exceeding $65 million. (Previously Senior Mental Health Counselor, 2004–2009.)
California Department of Corrections and Rehabilitation
Chief Psychologist. Directed statewide suicide prevention; subject matter expert for correctional behavioral health policy and system reform under the Coleman v. Brown settlement; competency, MDO, and SVP-related evaluations. (Previously Forensic Psychologist, 2009–2011.)
California Department of Managed Health Care
Behavioral Health Investigation Surveyor. Regulatory audits of commercial and behavioral health plans for compliance with the Knox-Keene Act, MHPAEA, and SB 855; authored findings incorporated into DMHC Final Survey Reports.
UC Davis — Sacramento, CA
Postdoctoral fellowship and residency, Department of Behavioral Health (APPIC accredited).
California School of Professional Psychology
Psy.D. and M.A., Clinical Psychology (APA accredited). MBA, Finance & Management — Texas A&M University (AACSB accredited). BA, Psychology & Criminal Justice Administration — National University.
Licensed to Practice — 13 States
All professional licenses are held in good standing, with no history of disciplinary action, sanctions, or malpractice claims. Dr. Mendonsa is retained by counsel nationwide; where an evaluation requires licensure in the forum state, he will confirm his standing in that jurisdiction before accepting the engagement.
Certifications & Board Recognition
A transparent method — built for Daubert and for cross-examination.
Admissibility turns on method, not conclusions. Every evaluation follows the same sequence: define the referral question, review the record, examine the person, administer validated instruments appropriate to that question, test response style, and state the limits of what the data support.
Validity, Effort & Response Style
SIRS-2, TOMM, and embedded validity indicators. Every forensic evaluation includes formal assessment of response style — the first question opposing counsel should ask, and the first one a defensible report answers.
SIRS-2 · TOMM
Personality & Psychopathology
MMPI-3 and PAI as the core objective personality measures, selected for their validity scales and their acceptance in med-legal and court settings.
MMPI-3 · PAI
Violence & Risk
HCR-20 for violence risk, VRAG-R actuarial risk appraisal, LS/CMI for criminogenic need and case management, STABLE-2007 for dynamic sexual-risk factors, and the PCL-R where psychopathy is at issue.
HCR-20 · VRAG-R · LS/CMI · STABLE-2007 · PCL-R
Suicide Risk
Columbia-Suicide Severity Rating Scale, together with BDI and BAI, applied within a structured professional judgment framework for foreseeability and standard-of-care analysis.
C-SSRS · BDI · BAI
Cognitive & Intellectual
WAIS-V, WISC-V, and WMS-V for intellectual and memory functioning where capacity, competency, or cognitive injury is in dispute.
WAIS-V · WISC-V · WMS-V
Adaptive & Neurodevelopmental
Vineland and ABAS for adaptive functioning; ADOS-2, SRS, and SCQ for autism spectrum and neurodevelopmental questions in both civil and criminal contexts.
Vineland · ABAS · ADOS-2 · SRS · SCQ
What a report from this office contains
The referral question as posed; the records reviewed, listed; the examination dates and duration; every instrument administered with scores and validity indices; collateral sources; the diagnostic formulation; the opinion, with its reasoning shown; and an explicit statement of the opinion’s limits and the alternatives considered and rejected.
What it does not contain
Opinions outside the referral question. Conclusions the testing does not support. Diagnoses reached without validity testing. Advocacy for the retaining party. Dr. Mendonsa’s responsibility runs to the evidence, the applicable professional standards, and the defined referral question — not to a preferred outcome or litigation position.
He teaches the subject he is asked to testify about.
Dual faculty appointment at the doctoral and undergraduate levels, peer review for the American Psychological Association, and enforcement review for the state licensing board — the standing within the professional community that qualification arguments rest on.
Governance, Peer Review & Public Service
- Expert Reviewer, California Board of Psychology Enforcement Unit
- APA Accreditation Site Visitor, American Psychological Association
- Peer Reviewer, American Psychological Association Divisions 12 and 18
- Chair and Board Director, Mountain Valley Child and Family Services
- Behavioral Health Subject Matter Expert Council Chair, Scouting America (Boy Scouts of America)
- Member, Faculty Technology Board, University of the Pacific
- Former Executive Board Member, California Coalition on Sex Offending (2015–2020)
- Former Member, El Dorado County Grand Jury; Placer County Mental Health Board; Sacramento County Alcohol and Drug Advisory Board
Awards & Recognition
Let’s discuss your case.
For psychological injury, workers’ compensation, disability, competency, risk, fitness-for-duty, licensing-board, or insurance-denial matters — reach out to discuss scope, timeline, and fees. Plaintiff, applicant, defense, and court-appointed retentions.