Our Team

NVMS Staff Members

Arleen Ramirez Borysiewicz, MPA, She/Her/Hers
Executive Director
Office hours: 9:00am-5:00pm, Monday-Friday
703.865.7260, aborysiewicz@nvms.us

Arleen has 25+ years of nonprofit experience, with expertise in management, fundraising, external affairs, community relations, board development, and branding and marketing. Her prior work includes serving as director of development and communications at United Community, a direct service agency supporting low-income families in Alexandria, Virginia. Before that, she was the primary fundraising officer at Ayuda, a Washington, D.C.- based legal immigration services nonprofit, and the vice president for external affairs at The Washington Center for Internships and Academic Seminars, also based in Washington, D.C. Arleen earned her Master of Public Administration from The George Washington University. She holds professional certifications in nonprofit management from Georgetown University, and in association management and diversity and leadership from the American Society of Association Executives. Arleen serves on the Board of Directors of Resolution Virginia. She is also a member of the Ayuda Advisory Council.

Guillerma Calles, She/Her/Hers
Family Mediation Program Coordinator
Office hours: 9am-5pm, Monday-Friday
703.865.7263, gcalles@nvms.us

Guillermina is not new to NVMS Conflict Resolution Center: she has been serving as Operations Coordinator since November 2021. Her training in the NVMS Basic Mediation Skills and Process course in 2021 and recent assignments to support family mediation screening and intake work make this transition seamless. Her Spanish language fluency has allowed NVMS to address the needs of Spanish-speaking community members calling for assistance, with care and clarity about disputes that they face. Guillermina worked as a bilingual real estate agent for Fairfax Realtors of Tysons and as administrative assistant at Escuela Argentina de Washington, DC. Guillermina received her law degree from the Universidad de Belgrano, Facultad de Derecho y Ciencias Sociales in Buenos Aires, and she earned her LLM in international legal studies from American University, Washington College of Law.

Samantha Simpore She/Her/Hers
Restorative Justice Program Coordinator
Office hours: 9am-5pm, Monday-Friday
703.972.9173, ssimpore@nvms.us

Samantha is a national restorative justice practitioner and consultant. She has over a decade of experience working with Washington, D.C. incarcerated and detained youth in an educational setting, as former executive director of Youth Escape Arena. She served as a behavior consultant/specialist and restorative justice practitioner with the See Forever Foundation-Maya Angelou Academy. In 2018, Samantha was invited to appear on Dateline NBC to talk about best practices on restorative justice circles. Samantha combines her executive and restorative practice skills with leadership experience, fundraising, event planning, and digital communication expertise. Samantha attended the University of Maryland. She also received the Georgetown University’s Center for Public and Nonprofit Executive Certification. Samantha lives in Alexandria, Virginia. 

Mark Preston, He/Him/His
Training Program Coordinator
Office hours: 9am-5pm, Monday-Friday
703.865.7261, mpreston@nvms.us

Mark is retiring from the U.S. Army. He has completed all the coursework for the Supreme Court of Virginia mediation certification. He also has been serving as a neutral on U.S. Department of Defense employee issues. We thank Mark for his military service. And we appreciate that he has chosen NVMS Conflict Resolution Center for the next chapter of his career.

Mark is an innovative, strategic, and goal-oriented leader, and we look forward to having him fortify our training program. Mark received his Master’s degree in legal studies at Washington University in St. Louis.  mpreston@nvms.us

Lydia Ray , She/Her/Hers
Court and Community Mediation Coordinator 
Office hours: 9am-5pm, Monday-Friday
703.865.7262, lydia.ray@nvms.us

For more than seven years, Lydia Ray has been utilizing her skills in alternative dispute resolution while expanding her knowledge and experience in conflict resolution in both domestic and international settings. Lydia is a Supreme Court of Virginia certified Juvenile and Domestic Relations and General District Court mediator. She had additional training in domestic violence assessment, ethics in mediation, mediation and communication, and restorative justice circles. Prior to joining NVMS Conflict Resolution Center, Lydia operated her private practice, Guided Mediation LLC, in Fairfax, Virginia. It is a family and community mediation practice that facilitates mediation sessions for families and individuals. She was the lead facilitator in guiding families through divorce and separation through the alternative dispute resolution process of mediation and conflict coaching sessions. She offered monthly blogs on topics related to conflict coaching, alternative dispute resolution themes and holistic approaches, tips and techniques of which Burnout and Vulnerability for the Win! have been featured on Mediate.com. Lydia earned a Bachelor in Global Affairs and Conflict Analysis from George Mason University.