Va. Code § 46.2-217
The Commissioner, his several assistants, including those who are full-time sworn members of the enforcement division of the Department of Motor Vehicles, and police officers appointed by him are vested with the powers of sheriffs for the purpose of enforcing the laws of the Commonwealth which the Commissioner is required to enforce. Such full-time sworn members of the enforcement division of the Department of Motor Vehicles are hereby authorized to enforce the criminal laws of the Commonwealth.
The Commissioner may also appoint or designate any of his staff to be "size and weight compliance agents" who shall thereby have the authority to (i) enforce the requirements for the use of dyed diesel fuel in §§ 58.1-2265 and 58.1-2267; (ii) enforce the requirements of Article 17 (§ 46.2-1122 et seq.) of Chapter 10; (iii) issue citations for violations of license, registration, and tax requirements and vehicle size limits pursuant to § 46.2-613.1; and (iv) carry out the vehicle seizure provisions of §§ 46.2-613.4, 46.2-613.5, 46.2-703, 46.2-1134, and 46.2-1136 at any permanent weighing station. For the purposes of this section, a permanent weighing station shall include any location equipped with fixed, permanent scales for weighing motor vehicles.
Nothing in this title shall relieve any law-enforcement officer, commissioner of the revenue, or any other official invested with police powers and duties, state or local, of the duty of assisting in the enforcement of such laws within the scope of his respective authority and duty.
All law-enforcement officers appointed by the Commissioner may administer oaths and take acknowledgments and affidavits incidental to the administration and enforcement of this title and all other laws relating to the operation of motor vehicles, applications for driver's licenses, and the collection and refunding of taxes levied on gasoline. They shall receive no compensation for administering oaths or taking acknowledgments.
Va. Code § 46.2-217