Leadership Team

Mr. Walton currently serves as Executive Director/CEO of CLARE|MATRIX in Santa Monica, California. He has an extensive background in healthcare in general and the treatment industry specifically having also served as the CEO for the High Watch Recovery Center located in Kent, Connecticut. Over the course of a thirty-five years, Mr. Walton has served as both a founder and a senior executive for a variety of private, public and non-profit enterprises. Mr. Walton has launched, grown and sold technology companies providing interactive network/Internet solutions for healthcare, energy, defense, Homeland Security and the public safety industries. Notable ventures include founding E Team, Inc. which pioneered the use of the Internet to manage events and emergencies including the 911 recovery in New York, multiple Super Bowls, two Olympics, natural disasters and pandemics. Other successful start up ventures include three heath tech companies: Clinically Home, SAMIHealth and Fitscript, LLC. In addition to his entrepreneurial career, Mr. has served as a management consultant and Managing Partner for a number of international consulting organizations. He was instrumental in founding the Emergency Interoperability Consortium (EIC) and served as its first chairman. Under his stewardship, the EIC partnered with the Department of Homeland Security to develop and proliferate the Common Alerting Protocol – the international data emergency communications standard that now facilitates alerts and warnings to over half the world’s population. He is a writer and speaker on topics related to health technology, cybersecurity and the challenges associated with artificial intelligence and the expanding Internet of Things. Mr. Walton has a BA from Brown University and an MBA from Yale School of Management.

Ken Simms is a proven professional in the Greater Los Angeles Area; he has over 20 years of experience working with small to medium-sized organizations as a key member of executive management. He has worked in multiple industries including service, technology, manufacturing, commercial real estate, and not-for-profit sectors. He has been responsible for business planning, strategic development, cash management, vendor management and monthly closing process. He specializes in systems conversions, operational streamlining. He has participated in due diligence for merger and acquisitions, post-acquisition restructuring, and implemented cost cutting initiatives. He has been responsible to report to bank officials and various board of directors. Additionally, he has managed numerous standard, forensic and municipal audits. Mr. Simms has a BA from the University of Southern California in Business Administration with an emphasis in Accounting.

Shireen Ossanlo is a seasoned development professional with over 15 years of experience in the nonprofit sector, holding director and executive roles for more than a decade. She has a diverse background that includes significant contributions to the YMCA and various inner-city schools within the Archdiocese of Los Angeles. Most recently, she served as the Executive Director for the Torrance Education Foundation, where she successfully supported 31 schools and 23,000 students annually.

Shireen has been with CLARE|MATRIX since 2021. Shireen has a proven track record in securing major gifts, managing high-impact events, developing transformative programs, and writing successful grants for both government and private funding. Her expertise lies in fostering donor relationships and driving organizational growth. She is skilled in board development, storytelling, annual giving campaigns, project management, content creation, CRM utilization, KPI tracking, budgeting, and social media marketing. In addition, she brings transferable skills in organizational operations, such as finance, budgeting, forecasting, human resources, DEI initiatives, and staff onboarding.

Specializing in board development, Shireen holds certificates from the Annenberg Foundation’s Alchemy and Alchemy+ programs and the Executive Service Corps’ Developing Development Program.  A native of West Los Angeles, she is deeply passionate about making a positive impact in her community. Shireen holds a Bachelor of Arts degree in Communications from California State University, Northridge, and is dedicated to advocating for those marginalized by society, continually striving to make a difference in people’s lives.

Donna L. Johnson has over 25 years of experience working with substance use disorders, criminal justice and integrated care. She has a long history of increasing profitably, growing and enhancing programs, while ensuring quality services for programs in all levels of care.  Donna has significant knowledge of legal/judicial issues and an excellent understanding of organizational systems and processes. She has a special interest in international work, providing consulting, Matrix model training and various behavioral health and criminal justice topics training to many countries that include: South Africa, Netherlands, New Zealand, Australia, Germany, Canada, United Kingdom, to name a few.   Donna believes that staff training, demonstration of skills and clinical supervisions are the keys to quality care and she values the role that Matrix offers to agencies through the training, consulting process and Key Supervision component.

Donna has been a consultant and trainer for the Matrix Institute on Addictions for over 17 years and is the lead author on the Matrix Model for Criminal Justice.  She has also worked as a contributor on several other Hazelden publications, and she is a trainer for Hazelden Betty Ford Foundation.  Donna has written numerous magazine articles and has been featured on CBS Atlanta, PBS, CNN and Fox News on various addiction issues.

She served as the Director for a large community mental health center, overseeing all levels of care including detox, inpatient, crisis stabilization, intensive outpatient, residential, women’s programs and adolescent services.  In addition, she worked in several areas of the criminal justice system including:  corrections, drug courts, community supervision and youth justice.  Donna also worked with a large hospital system to integrate behavioral health and trauma informed care into their primary care system.

Donna founded her own company, Addiction Solutions of Georgia, Inc., where she specialized in consulting and training in substance use disorders, criminal justice, tele-mental health and integrated care. She has provided consulting and training to numerous state addiction authorities, CSAT projects, hospitals, drug courts, agencies, Fortune 500 companies and many criminal justice programs.  Donna has been a speaker and keynote for numerous national and international conferences, including the National Association for Drug Court Professionals Conference and the National Conference on Addictive Disorders and the United Kingdom and European Symposium on Addictive Disorders.

Mary is an accomplished leader in the nonprofit sector, specializing in Foster Care, Adoption, Group Homes, and Residential Substance Use Disorder Treatment. With 15 years of experience, she excels at cultivating teams and overseeing residential programs. Originally hired as the Men’s Residential Treatment Program Manager, Mary now oversees both Men’s and Women’s facilities as the Director of Residential Services. Mary earned her credentials in Clinical Psychology with an emphasis in Marital and Family Therapy from California State University Dominguez Hills.

Jon Quach, MD, received his Bachelor of Science in Biochemistry and Cell Biology, Summa Cum Laude, from University of California, San Diego and his Doctor of Medicine from New York University School of Medicine. He is board certified in internal medicine and addiction medicine.

Dr. Quach completed both an internal medicine residency and addiction medicine fellowship at University of California, Los Angeles (UCLA) Medical Center. He was previously an assistant professor of internal medicine and served as a teaching attending at UCLA Ronald Reagan Hospital and UCLA Santa Monica Hospital. He oversaw the training of interns, residents, and medical students at the David Geffen School of Medicine at UCLA.

Dr. Quach co-founded and manages the UCLA-RR Inpatient Addiction Consult Service and UCLA Bridge Clinic for patients suffering with substance use disorders at UCLA Health. He oversees the training of fellows from the UCLA Health/Eisenhower Addiction Medicine Fellowship at CLARE|Matrix, which serves as a training site for multiple academic programs in Los Angeles County.