Correction: A previous version of this article misspelled the name of a lawyer who handled one of the cases. His name is Eric Clingan, not Eric Klingan. This version has been corrected.

A judge has dismissed four drunk-driving cases initiated by the same Fairfax County police officer after he failed to record sobriety tests using his cruiser’s audio and video systems, according to attorneys and court filings.

Attorneys argued that the failure violated police orders and deprived their clients of potentially exculpatory evidence in each case. In some cases, attorneys said defendants’ accounts of the stops varied from those provided by Officer L.F. Martinez.

“When you’ve got this type of equipment, it’s there for everyone’s protection,” said Eric Clingan, a lawyer who handled one of the cases. “It protects the police as much as the citizen.”

Dashcam video of Martinez’s stop of Clingan’s client Dec. 8 shows the officer standing next to the man’s car in the Fair Lakes area. The officer opens the man’s door, and the man follows the officer across the camera frame and then off-screen, where the sobriety test was to be performed. Court filings say the audio recording system was also turned off.

Later, the man was charged with refusing to take a sobriety test and with his second DWI within 10 years. The Washington Post is not naming the man because charges against him have been dismissed.

Under Fairfax County police general orders, officers are required to test their audio and video recording equipment before a shift and utilize both during traffic stops. Officers are also encouraged to film sobriety tests.

Martinez could not immediately be reached for comment. Fairfax police declined to discuss the specific cases that were dismissed or the judge’s ruling. But county police spokesman Don Gotthardt noted that “there is no specific requirement that the officer conducting a sobriety stop keep the subject within view of the camera.”

Clingan said the officer testified that he moved suspects off camera to perform sobriety tests in some instances to find level ground. He also testified he was reluctant to leave the suspects alone to swivel the camera in the proper direction to film the tests.

Attorneys said there were disagreements between the defendants and Martinez about factual matters, but there was no evidence that the officer intentionally conducted the tests out of view of the camera.

“The fact that the client’s versions differed so much from officer’s versions was probably a deciding factor for the court,” attorney Justin J. Weiss said. “However, it was clear that the court found a pattern of inadvertent failure to follow proper procedures with the audio and dashcam.”