When New Mexico's DWI laws are tweaked or altered, generally prosecutors receive more tools to fight drunken drivers.

However, a decision handed down earlier this week by the state Supreme Court will make it more difficult for prosecutors because they "will now have to look closer at the facts of (DWI) cases," said Santa Fe District Attorney Angela "Spence" Pacheco.

Before the unanimous decision — known as State v. Sims — an intoxicated driver found in a car that wasn't moving could be cited and convicted for driving while intoxicated simply because the driver might have driven the car. Now, prosecutors must prove the driver "was actually, not just potentially, exercising control over the vehicle, and ... the defendant had the general intent to drive," according to Tuesday's decision.

"(Before) it was a little more automatic if the person was in the car," Pacheco said. "Now we have to figure out intent, and sometimes we have that information and sometimes we don't."

Defense attorneys, on the other hand, cheered the decision, and said it will allow people who decide not to drive or those against whom there is no evidence they ever drove to avoid a DWI charge.

"It's very important for the small number of DWI cases this represents," said Ben Baur, district defender for the First Judicial District, which includes Santa Fe, Los Alamos and Rio Arriba counties, and president of the New Mexico Criminal Defense Lawyers Association. "It's not weakening (DWI law), but it's narrowing the application of the law. It really brings some common sense to the application of DWI law."

The case at the heart of the decision involved a man named Mark Sims, whom police found asleep behind the wheel of his car in a commercial parking lot with the keys on the passenger seat. Sims later failed sobriety tests and was found to have a breath-alcohol content of .19, more than double the legal driving limit.

He pleaded guilty to one count of DWI in Metropolitan Court in Albuquerque in December 2004, but appealed the conviction.

In looking at the case, Supreme Court justices decided that previous precedent-setting cases went too far in defining a drunken driver whose vehicle was never seen moving by a police officer.

Those precedents held that a driver must have continuing "actual physical control" over the vehicle in order to be convicted of a DWI an officer didn't witness — for example, when someone is found passed out behind the wheel at a stoplight. That precedent was later interpreted to include any driver found intoxicated in a stopped car.

Justices recognized in the new decision that sometimes people might get into their cars and decide not to drive — thereby using the vehicle as a temporary shelter. They said factors such as whether the engine was running, the position of the vehicle, weather conditions and other variables must now be taken into account when deciding such a driver's guilt.

"More care will be required of investigating officers and prosecutors to establish facts tending to prove that defendants actually used their vehicles with the general intent to drive and posed a real danger to themselves or the public," according to the decision written by Chief Justice Edward Chavez. "A totality of the circumstances test must prove what defendants have done and what they intend to do, not merely what they might do."

Aaron Boland, a local defense attorney, said he had a client about a year and a half ago who exactly fit the circumstances outlined in the new decision. A jury convicted the man after he decided not to drive, went to sleep in his car, was caught by police and was charged with DWI, he said. The man didn't have the money to appeal the judgment, Boland said.

"It's an excellent decision," he said. "It makes a lot of sense."

Tom Clark, another defense attorney, agreed, saying the law before the decision was "a slippery slope." For example, what if an intoxicated person was found walking to his car with the keys in his hand, or unlocking the car? Could that person be charged with DWI? Clark asked.

Clark also said he defended a juvenile whose parents told him and a friend to go outside because they were intoxicated, and they were charged with DWI when police found them listening to the car radio outside the home.

"It punishes possible future behavior, which is terribly unconstitutional," he said. "It's not going to help a substantial amount of DWI drivers. It will help when an absurd fact pattern occurs."

Santa Fe County Sheriff Greg Solano said he hadn't heard of many DWIs that fit the fact pattern outlined in the new decision. In fact, he said he probably wouldn't have arrested Sims if he'd encountered him sleeping in his car in the parking lot.

Still, he conceded that the law "needed to be clarified."

Rachel O'Connor, the state's DWI czar, said she thinks the law will have an impact, though she isn't yet certain how it will play out. She said she isn't sure the decision will weaken DWI law, but is concerned about the potential for abuse.

Contact Jason Auslander at 986-3076 or jauslander@sfnewmexican.com.