Paraphrased from 46.2-1079:
§ 46.2-1079. Radar detectors; demerit points not to be awarded.
A. It shall be unlawful for any person to operate a motor vehicle on the highways of the Commonwealth when such vehicle is equipped with any device or mechanism, passive or active, to detect or purposefully interfere with or diminish the measurement capabilities of any radar, laser, or other device or mechanism employed by law-enforcement personnel to measure the speed of motor vehicles on the highways of the Commonwealth for law-enforcement purposes. It shall be unlawful to use any such device or mechanism on any such motor vehicle on the highways. It shall be unlawful to sell any such device or mechanism in the Commonwealth. However, provisions of this section shall not apply to any receiver of radio waves utilized for lawful purposes to receive any signal from a frequency lawfully licensed by any state or federal agency.
B. A person shall not be guilty of a violation of this section when the device or mechanism in question, at the time of the alleged offense, had no power source and was not readily accessible for use by the driver or any passenger in the vehicle.
C. This section shall not apply to motor vehicles owned by the Commonwealth or any political subdivision thereof and used by law-enforcement officers in their official duties, nor to the sale of any such device or mechanism to law-enforcement agencies for use in their official duties.
D. No demerit points shall be awarded by the Commissioner for violations of this section. Any demerit points awarded by the Commissioner prior to July 1, 1992, for any violation of this section shall be rescinded and the driving record of any person awarded demerit points for a violation of this section shall be amended to reflect such rescission.
In short, you can be in possession or a federally approved detection or “jammer” but cannot be used within the commonwealth of VA. The code is pretty black and white.