Jonathan Casteline

Jonathan Casteline is an adjunct faculty member in the Department of Criminology, Law, and Society at George Mason University. Mr. Casteline currently serves as a Lieutenant with the Manassas City Police Department, where he has dedicated more than a decade to public service in both patrol and administrative leadership roles. Throughout his career, he has maintained a strong commitment to community-oriented policing, focusing on building trust, fostering partnerships, and enhancing collaboration between law enforcement and the communities they serve.

During his tenure with the department, Mr. Casteline has held numerous assignments, including Watch Commander, Field Training Officer, Emergency Services Unit member, Honor Guard member, and department instructor. He previously served within the Training and Recruitment Unit, where he played a key role in officer development, hiring initiatives, and community engagement efforts. As a Public Information Officer, he has also worked to provide clear, transparent, and timely communication to the public during critical incidents and community events.

A significant focus of Mr. Casteline’s professional and instructional experience involves emergency preparedness and active-attack response training. He has instructed both law enforcement officers and community members on active-attack preparedness, emphasizing situational awareness, coordinated response strategies, and practical safety measures designed to better prepare individuals, schools, businesses, and organizations for critical incidents.

Before entering law enforcement, Mr. Casteline served in the United States Marine Corps for eight years and continued serving his community in various public service roles. He is currently a member of the International Association of Chiefs of Police and the Fraternal Order of Police.