Being arrested for driving under the influence of alcohol (DUI) can cost a motorist thousands of dollars in court fines, insurance costs and attorneys' fees. At least 79 accused drivers were notified last Friday that the police officer that charged them with drunk driving had likely falsified at least one piece of evidence. Sacramento County District Attorney Jan Scully threw out the cases after an investigation into the conduct of Sacramento Police Officer Brandon Mullock, 24.

Scully opened the inquiry into Mullock's conduct after a deputy district attorney preparing a DUI case for trial watched a dashcam arrest video and noticed that the raw footage differed substantially from Mullock's written account of the incident in a police report. The case was dropped in June.

"It is fundamental to our system of justice that prosecutors only proceed on cases where the evidence is trustworthy and was legally obtained," Scully said in a statement. "The United States Supreme Court has said that the prosecutor should seek not simply to win a case, but to see that justice is done. The California Supreme Court has said that public prosecutors are charged with the important and solemn duty to ensure that justice and fairness remain the touchstone of our criminal justice system."

According to Scully's office, most of the defendants were convicted in a court of law despite Mullock's legally unsound decision to detain the motorists, despite his misuse of preliminary alcohol screening and despite wild inaccuracies in his field interviews.

"Drunk driving is one if those crimes which is highly susceptible to falsifying evidence," California DUI attorney Lawrence Taylor explained on DUI blog. "This is because the offense is highly dependent on the cop's own observations and opinion. Typically, proving 'driving under the influence of alcohol' depends upon the officer's testimony of such symptoms as weaving on the highway, odor of alcohol on the breath, flushed face, slurred speech, bloodshot eyes, poor balance, staggering when walking, etc. Usually, there are no other witnesses to contradict these 'observations'; certainly, no one will believe the accused... The motive? Fulfilling quotas, overtime pay for testifying in court, promotions for high numbers of arrests, gaining awards in personnel files from MADD, etc."

The district attorney's office has provided each convicted motorist with documentation they can provide to insurance companies and employers to remedy some of the damage done.