Dwayne A. Preston began a career in law enforcement with the Prince George’s County Police Department in 1990. He served the department for 21 years before retiring from the agency as the Deputy Chief of the Bureau of Administration in December 2011.

On January 1, 2012, Deputy Chief Preston continued his law enforcement career when he joined the Bowie Police Department. In this position, he oversees the department's daily operations, is the principal author of the department’s strategic plan, oversees internal investigations, and implements the department’s body-worn camera program. Deputy Chief Preston was asked to serve on the Police Reform Taskforce convened by County Executive Angela Alsobrooks. This was an important role and provided an opportunity to offer recommendations that would improve the Prince George’s County Police Department and the policing profession in general. In mid-September, Deputy Chief Preston assumed the role of Acting Chief of Police.

He is a proud graduate of DeMatha Catholic High School. He obtained his Bachelor’s Degree in Business Administration with a concentration in Accounting from Bowie State University and an MBA from University of Maryland University College. He believes that his education in business has assisted him in being an effective leader in managing complex budgets and utilizing resources efficiently.