PHOENIX (AP) - Medical-marijuana cardholders in Arizona who drive after using the drug may face a difficult legal choice: their driver's license or their marijuana card. If they use both, they could be charged with DUI.
Valley prosecutors say that any trace of marijuana in a driver's blood is enough to charge a motorist with driving under the influence of drugs and that a card authorizing use of medical pot is no defense.
But advocates of medical marijuana, which voters approved in November 2010, argue that the presence of marijuana in a person's bloodstream is not grounds for charging drivers who are allowed to use the drug.
The legal battle over the rights of medical-marijuana cardholders to drive while medicating is being fought in the state's court system. Motorists convicted in municipal courts, which typically rule it unlawful for a driver to have any trace of marijuana in his or her blood, are appealing cases to Superior Court, where judges' decisions could set precedents for how the medical-marijuana law applies to Arizona drivers.
Eighteen states and the District of Columbia authorize the use of marijuana for medical purposes, making marijuana-related DUIs an issue for police, prosecutors and politicians nationwide.
The biggest issue is deciding what blood level of marijuana makes a driver impaired, similar to the way blood-alcohol levels determine when a person is legally drunk.
In Arizona, the confusion over interpretation of the Medical Marijuana Act stems from its inception because prosecutors and police didn't have the chance to weigh in before it went to voters in 2010.
Prosecutors say Arizona law allows motorists who are not impaired to drive with prescription drugs in their system if they are using them under doctors' orders.
The problem for marijuana cardholders is that pot can't be prescribed, only recommended, offering no legal grounds for a motorist to drive with even trace amounts of the drug in their system, according to prosecutors.
For most driving-under-the-influence-of-marijuana cases, the drug charge is secondary to the charge of driving while impaired. Arizona's DUI laws have three aspects: driving while impaired to the slightest degree, driving under the influence of alcohol and driving under the influence of drugs.
The handful of cases making their way through the courts grew out of traffic stops, where drivers are typically cited for both driving while impaired to the slightest degree and driving under the influence of drugs.
Attorneys for the accused say they are willing to argue about impairment, which would allow a drug expert hired by the defense to counter testimony from a police drug-recognition expert, but that a suspect's legal participation in the state's medical-marijuana program should provide a defense to the DUI-drug charge if there is no evidence of impairment.
Prosecutors in Mesa and other jurisdictions have successfully argued to keep juries from hearing information about a suspect's medical-marijuana card, which could be appealed.
"They can make that argument (about impairment) and I think it's a fair one to make. What they can't do is preclude a jury from hearing that he has a medical-marijuana card," said Craig Rosenstein, an attorney representing a DUI-drug suspect in Mesa. "The idea that he would be able to beat the (DUI-drug) charge is impossible unless the jury can hear that they have a medical-marijuana card. Otherwise, he's just a kid smoking weed and he got caught."
Morgan Jackson Doyle, 24, was coming back from the Salt River on Memorial Day 2012 when he was stopped at a sobriety checkpoint by Mesa police near Power Road and the Red Mountain Freeway.
An officer said Doyle had reddened eyes and a raspy voice, which prompted him to ask whether Doyle had recently smoked marijuana, according to police.
Rosenstein, Doyle's lawyer, said Doyle gave the officer his medical-marijuana card with his driver's license, "out of an abundance of truth."
Doyle was put through a series of field-sobriety tests, some of which indicated impairment while others did not, before a trained drug-recognition officer was called to put Doyle through more thorough tests that look for clues of drug use.
The drug-recognition expert determined it was not safe for Doyle to drive, police said. He was cited for driving while impaired to the slightest degree and driving under the influence of drugs.
Blood tests later showed Doyle had the psychoactive component of marijuana in his blood, but in an amount that falls below levels some scientists consider the threshold for impairment.
A judge in Mesa refused to allow Doyle to introduce the card at his trial, prompting his lawyer to seek a ruling in Superior Court, which sent the case back to Mesa. If the court rules as expected, attorneys said the case will be appealed.
"I think it's ridiculous. Voters in Arizona adopted the Medical Marijuana Act, whether politicians agree or not," Rosenstein said. "My concern was, if this isn't isolated to Mesa, in theory that could make bad law for the entire state."
Phoenix prosecutors have taken the same stance on drug DUIs for marijuana cardholders, in part, because the drug does not come with any of the same controls as a standard prescription, said Beth Barnes, the city's traffic-safety resource prosecutor.
The potency of marijuana can vary among dispensaries that sell to patients, and doctors' recommendations do not have dosage limits and warning against operating heavy machinery that prescriptions usually carry, she said.
Those and other factors mean possession of a card is not relevant in DUI cases, Barnes said.
Aaron Carreón-Ainsa, Phoenix's chief prosecutor, said he understands it is legal for authorized patients to use medical marijuana, but that right can infringe on other privileges they might enjoy.
"For those people who have medical-marijuana cards, OK, it's legal. Fine," Carreón-Ainsa said. "But don't come to this building because you've been driving. Just take it and don't drive."
Though some states have tried to attach a number to impairment, experts say the practice is complicated by a number of factors including the patient's metabolism and smoking frequency.
A 10-year study of more than 8,700 DUI-drug cases in Sweden led researchers to conclude that zero-tolerance policies were probably most effective because they help identify suspects whose concentration-level might have fallen below an arbitrarily set limit while waiting to give a blood sample.
"Scientists have found it virtually impossible to agree upon the concentration of a psychoactive substance in blood that leads to impairment in the vast majority of people," the researchers wrote.
Colorado legislators consistently rejected proposals to link impairment with a particular amount of marijuana in a driver's blood, but this year passed a law allowing prosecutors to presume impairment if that level is above 5 nanograms per milliliter. Defense attorneys argue that 5 nanograms is an arbitrary amount that has no bearing on impairment.
"We need to stop looking at a meaningless number, and in the case of Arizona, not only a meaningless number but a cruel and unusual application of it: you punish somebody on a Monday morning for them killing their pain on a Friday night," said Lenny Frieling, a Colorado attorney and medical-marijuana advocate.
"I don't want impaired drivers on the road. The key in my mind is looking at whether somebody really is or is not impaired. If they're impaired, I don't care which drug impaired them."
Frieling is developing a mobile test that gauges factors, including memory and balance, that could help determine impairment, but without years of clinical trials and research about marijuana concentrations that equate to impairment, the issue often relies on police drug-recognition experts and interpretation of state laws.
Courts within the same states have been inconsistent in applying the law.
A Michigan man was charged with driving a car with a prohibited substance in his system after he told an officer during a traffic stop that he was an authorized medical-marijuana cardholder and had smoked five hours earlier.
A judge concluded that the state's medical-marijuana law protected him from prosecution unless police could prove he was impaired. Another court agreed before the Michigan Court of Appeals reversed the judge's order and determined that legislators deemed it unsafe for a motorist to drive with any amount of marijuana in their system.
The Michigan Supreme Court reversed that Appeals Court decision earlier this year and found that the state's medical-marijuana law authorized participants to have traces of marijuana in their bloodstream so long as they were not impaired while driving.
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