Campbell County Attorney Justin Verst said he made the decision after viewing a cruiser video of the stop that shows the sergeant repeatedly refusing to take a field sobriety test and being uncooperative. A Fort Thomas police officer had stopped Mark Crank, who was off-duty and driving a family member's car.

But criminal attorneys - and even members of Mothers Against Drunk Driving - said it will be a hard case to prove.

The sergeant will be arraigned in Campbell District Court Thursday morning on a misdemeanor charge of driving under the influence. The charge carries a maximum penalty of 30 days in jail and a $500 fine.

"This will be a very tough case for the commonwealth," said attorney Burr Travis of Florence, who has represented thousands of drivers charged with driving drunk in Northern Kentucky. "The general rule is without evidence, such as a breath test, blood test or field test, a conviction should not occur."

Travis, who is not representing anyone involved in the Crank case, said the video would have to demonstrate to the jury, beyond a reasonable doubt, that the sergeant was driving drunk.

Sara McKinney, vice chair for MADD Kentucky, applauded Verst's decision to prosecute, but agreed it will be an uphill battle.

"From my experience, without some evidence from a test, prosecutors can't get a conviction," said McKinney of Louisville. "I guess this case will depend on the officer's behavior in the video."

Verst said it would not be ethical for him to comment on the merits of his case, but said he had spoken with various witnesses before making a decision.

"I think it is important every defendant be treated the same, no matter who they are," he said. "It is the only way the justice system can function properly."

Verst, whose office is in charge of prosecuting all drunken driving cases in Campbell County, said he had received complaints from citizens who were upset Crank wasn't charged.

Newport Police Chief Tom Fromme, who couldn't be reached Tuesday for comment, had previously said Crank would be suspended for three to five days without pay.Crank also couldn't be reached Tuesday for comment.

The video shows Fort Thomas Police Officer Adam Brown pulling over Crank's car shortly after 1 a.m. Aug. 10 on the Interstate 471 ramp to Interstate 275 west.

"The bottom line is, you are DUI," Brown is heard saying on the videotape. "You know it, and I know it. I'm obligated by state law and I am obligated by ethics to treat you just like I do anybody else."

But after Crank refused a field sobriety test, Brown allowed someone to drive Crank home.

Brown and his sergeant, Todd Dedman, were counseled for their decision. In Kentucky, there is no law requiring an officer to cite a drunken driver.

E-mail jhannah@enquirer.com