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Legal issues of inventing a breath test to detect drugs – Part II

On behalf of Harper, Evans, Hilbrenner & Netemeyer

Dec 09, 2014

In one of our blog posts last week we brought to our Missouri readers’ attention the fact that scientists are currently looking into a new way of detecting if a driver is impaired by drugs. As you may remember from the post, a chemistry professor from Washington State University believes that it’s possible to adapt a Breathalyzer device to detect THC rather than alcohol. And if researchers are successful, then this device could become a regular tool for law enforcement across the nation.


But as we mentioned last week, such a test may create some legal issues for residents here in Missouri, which is a concern not just for our readers here in Boone County but across the state.


The first foreseeable issue has to with how our state handles drugged driving. Here in Missouri, marijuana use is illegal, meaning even the presence of such a drug in a person’s system can lead to criminal charges. In fact, according to the Missouri Department of Transportation, “if you use drugs and drive, you will be charged with a DWI even if you do not have alcohol in your system.” But according to the National Highway Traffic Safety Administration, the presence of THC in a person’s system is not enough to indicate impairment.


As the NHTSA explains, “it is difficult to establish a relationship between a person’s THC blood or plasma concentration and performance impairing effects.” That’s because impairment is contingent upon several variables including frequency of use and when the drug was used. As you can see, this creates a potential problem for a Missouri driver because they could be accused of impaired driving even though they may not be impaired.


It’s important to also consider how the law will govern the use of such a device. Will the requirements for its use be similar to current Breathalyzer tests? Will a refusal to take either an alcohol or drug breath test result in a single infraction or could someone face two penalties for refusing the tests? How will the courts handle such cases down the road?


It’s questions such as this that our readers may need to ask themselves, especially because they could easily arise in future criminal cases if the drug breath test device is created. The hope though is that legislators will have addressed these potential issues by then so that they don’t become problems later on.


Source: The National Highway Traffic Safety Administration, “Cannabis / Marijuana,” Accessed Dec. 9, 2014

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