South Carolina has one of the worst records for DUI deaths, but it's not always easy to convict drunk drivers in court.

The issue resurfaced recently when Charleston Police Chief Greg Mullen said the difficulty of getting a DUI conviction in South Carolina was one of the reasons an officer charged an apparently intoxicated woman sitting behind the wheel of car outside a downtown hotel with disorderly conduct instead of drunk driving.

Former CARTA Director Christine Wilkinson was charged with disorderly conduct instead of DUI because a video camera wasn't immediately available and the officer didn't see her driving, even though the officer said she smelled of alcohol, was slurring her speech and her eyes were bloodshot, Mullen said.

"Certainly there were witnesses there, but based on our history, knowing the difficulty we have with DUIs, since he didn't have a camera or immediate access to one, and he didn't see her driving, after talking with his supervisor, he felt the best resolution was to go ahead and charge her with the disorderly conduct to resolve the immediate situation," Mullen said.

A DUI arrest is complicated and takes an officer off the street for several hours, not including the time the officer has to spend in court.

State law requires that DUI field tests, arrests and breath tests at the station be videotaped. South Carolina does not allow portable breath testing.

The video recording of a DUI arrest is so crucial to a conviction that a flaw in the recording can get the whole case thrown out of court. That's what happened after then-state Sen. Randy Scott of Summerville was arrested and charged with DUI in 2008. The judge dismissed the case when defense attorneys pointed out a gap in the audio on the recording.

Cases get thrown out all the time after lawyers attack the video, according to Steve Burritt, spokesman for the state chapter of Mothers Against Drunk Driving.

"It's one of the most common issues I hear about," Burritt said. "Compared to every state, we have a much higher burden of video recording."

He cited several recent examples. A case was thrown out when a driver performing a heel-to-toe walk took too many steps and went off the video. Another case was dismissed after the defense argued that the video was too dark to see the driver's eyes.

MADD tried last year to get an amendment passed that would specify that a video recording does not have to be 100 percent perfect to be admissible. The bill to which the amendment was attached didn't pass.

"The expectation that you have to have a perfect recording means too many people are getting off, in a state that is absolutely one of the worst in the nation for drunk driving," Burritt said.

The ranking is based on comparing the number of deaths with miles traveled. In 2012, South Carolina had 0.73 DUI fatalities for every million miles traveled, according to the National Highway Traffic Safety Administration. That's more than twice the national average of 0.35.

DUI lawyers use the videotape requirements to their advantage.

"That's one of the first things we look for is defects in the video," Mount Pleasant attorney Edward Phipps said.

He got a case tossed out because the person's legs weren't visible on the video during the heel-to-toe test.

He mentioned a few other cases that are held up as precedents. In 2011, the S.C. Supreme Court dismissed a DUI conviction because the officer's tape in his camera ran out. The case was City of Rock Hill v. Suchenski.

In 2007, the state's high court dismissed a DUI case after Mount Pleasant police said they didn't record the arrest because the car didn't have a video camera. The court said the town should buy more cameras. The case was Town of Mount Pleasant v. Robert.

Phipps is a former Mount Pleasant police officer. He says he's still on the cops' side and is making sure the system is working like it should.

"I do have friends who say, 'You're like Darth Vader. You went to the Dark Side,'" he said. "When I was a police officer, I dotted my I's and crossed my T's. Now I'm making sure officers dot their I's and cross their T's. My blood runs blue. I'm a check and balance."

Ironically, several websites list South Carolina as one of the toughest states when it comes to penalties for a DUI conviction. A first offense can cost you a $400 fine plus court costs, you could get your license suspended for three months, and you will be required to complete a safety program to get your license back.

The state recently passed a law, known as Emma's law, that requires anybody convicted of DUI - even a first offender - with a blood alcohol level greater than 0.15 to install an ignition lock in the car for six months. The driver has to blow in it before the car will start. The car will only start if the device doesn't measure a significant amount of alcohol.

But the way the state's DUI laws are written makes it more difficult in South Carolina than in many other states to convict an intoxicated person sitting in a parked car.

While many states' DUI laws talk about "operating a motor vehicle," S.C. law specifies "driving a motor vehicle." The language would have made it hard to convict Wilkinson of DUI, attorney Tim Kulp said.

"It's easy to make an arrest," he said. "It's harder to get a conviction."

Kulp is a former city prosecutor and FBI agent. He has a great distrust for the machines that measure blood alcohol. He will point out defects in the video and then undermine the jury's confidence in the DataMaster that measures alcohol in the breath.

"It's a crime of a unique grayness," he said of a DUI charge.

An officer can arrest a person for DUI on probable cause, but a jury must be convinced beyond a reasonable doubt to find the person guilty, he points out.

Wilkinson asked the officer who arrested her to let her off the hook because she worked for the city, according to the incident report. But she made that request after the officer already told her she was being charged with disorderly conduct. He made the decision to charge her with disorderly conduct after telling his supervisor he didn't see her driving, according to the report. She resigned after the arrest became public.

Mullen said there is no indication Wilkinson got special treatment.

"I don't think arresting anybody for disorderly conduct and public intoxication and taking them to jail is any preferential treatment in any way, shape or form," Mullen said.