It is the purpose of this article to provide more effective protection of society by establishing pretrial services agencies that will assist judicial officers in discharging their duties pursuant to Article 1 (§ 19.2-119 et seq.) of Chapter 9. Such agencies are intended to provide better information and services for use by judicial officers in determining the risk to public safety and the assurance of appearance of persons age 18 or over or persons under the age of 18 who have been transferred for trial as adults held in custody and charged with an offense, other than an offense punishable as a Class 1 felony, who are pending trial or hearing. Any city, county or combination thereof may establish a pretrial services agency and any city, county or combination thereof required to submit a community-based corrections plan pursuant to § 53.1-82.1 shall establish a pretrial services agency.