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DWI Breath Tests for Marijuana : Here, Coming, or Only Imagined?

 Posted on November 11, 2022 in Uncategorized

Police have been using alcohol breathalyzers for decades to detect potential DWI offenses, despite the unreliability of alcohol breathalyzers. Houston police use the Intoxilyzer 9000 breathalyzer to infer your blood alcohol concentration for DWI charges. Houston prosecutors can convict on a Texas DWI using breathalyzer results, but a skilled Texas DWI Specialist's cross-examination can often discredit the results. That's pretty much the landscape for alcohol breathalyzers: in common use but subject to challenge. Yet what about a marijuana breathalyzer? Driving while impaired by marijuana is a Texas DWI crime, chargeable under Texas Penal Code Section 49.04 just like alcohol DWI. You may have seen or heard about advertisements for marijuana breathalyzers. They're out there, on the market. But are drivers facing marijuana breathalyzer tests, and if so, are the results admissible to support marijuana DWI charges?

The Current Science on Marijuana Breathalyzers

According to media reports, the first marijuana breathalyzers on the market claimed to detect marijuana compounds when present in the tested person's bloodstream. The problem, though, is that those compounds can remain in a person's blood for days or even weeks, well beyond the point at which marijuana's intoxicating effect would have worn off, typically within a couple or few hours. A marijuana breathalyzer that says the person ingested marijuana compounds sometime within, say, the last month isn't of any particular use in proving intoxicated driving. That's why police in Houston weren't generally using those first marijuana breathalyzers, and if they were, their results wouldn't likely have been admissible. But according to the same media reports, newer marijuana breathalyzers are claiming to test for marijuana compounds lingering in the breath from smoking within the past couple of hours. That adaptation arguably addresses the concern over past marijuana ingestion. Drivers could soon see greater police use of marijuana breathalyzers and more prosecutors arguing for their result's admissibility to support DWI charges.

Legal Problems Setting a Marijuana Benchmark

Yet marijuana breathalyzers still face another problem: research hasn't yet established a numerical benchmark for marijuana, tied to the necessary driver impairment. Texas Penal Code Section 49.04 permits Houston prosecutors to charge a driver with DWI when marijuana use has deprived the driver of the normal use of mental or physical faculties. But no one knows exactly what level of marijuana's active compound in the blood or breath equates to impairment. Prosecutors may charge a Texas alcohol DWI on a.08 or higher blood alcohol content. But neither Texas law nor marijuana science can tell prosecutors, drivers, or defense attorneys what level of marijuana's active compound in the breath or blood indicates impairment. Marijuana DWI charges still depend on officer testimony or other evidence of the driver's actual impairment, plus evidence of some marijuana use, although no one knows how much use. Impairment is the thing, not marijuana numbers. You shouldn't suffer conviction solely on evidence of a positive marijuana test, without impairment evidence. And unless something fundamental changes in the marijuana research, we may not see any specific marijuana compound level, like alcohol's.08, become impairment evidence soon.

Practical Problems Setting a Marijuana Guide

But it's not all good news for drivers who ingest marijuana. Just as police and prosecutors don't have a specific breathalyzer reading to say that marijuana use has impaired a driver, drivers don't have a specific breathalyzer reading to say that marijuana use has not impaired the driver. Indeed, a Congressional Research Service report indicates that while studies suggest that about two alcoholic drinks in one hour can affect a 160-pound male's vision and executive function, as a very rough guide for responsible alcohol consumption, no similar guide exists for marijuana. Marijuana users just don't know when enough is enough, and too much is too much. So, if you've heard that marijuana breathalyzer results alone can get you convicted for a Texas DWI, you're hearing another DWI misconception. But if you're hearing that one or two joints is fine while three or four is not, that information, too, is untrustworthy. Impairment of normal mental or physical faculties is the standard, not any numerical guide.

DWI Defense in Marijuana Cases

Just because marijuana DWI cases don't go by the seemingly hard-and-fast numbers of an alcohol DWI, doesn't mean that you can't raise a strong defense. Your retained Texas DWI Specialist defense attorney can raise most of the same defenses in your marijuana DWI case as in an alcohol DWI case. For example, prosecutors often charge marijuana and alcohol DWI cases based on video evidence, eyewitness testimony, and other direct and circumstantial evidence of alleged impairment. But each form of evidence has its own limitations, even including the surprisingly unreliable eyewitness observation. Your DWI Specialist's advocacy skills can reveal the contradictions, weaknesses, and limitations in that evidence. You may also have other strong DWI defenses, such as that police lacked probable cause for your DWI stop or reasonable suspicion that marijuana was impairing your faculties. Authorities may also have violated your constitutional rights so that your DWI Specialist defense attorney can move to suppress incriminating evidence.

Retain Houston DWI Specialist Defense

The best thing you can do when facing DWI charges relating to marijuana use is to promptly retain DWI Specialist defense attorney Doug Murphy. Attorney Murphy is the 2023 Houston DWI Lawyer of the Year according to Best Lawyers in America. Attorney Murphy is not only a Board Certified DWI Specialist but also holds both DWI Board Certification and Criminal Law Certification. Indeed, attorney Murphy is one of only two attorneys in Texas to hold both specialist certifications. Attorney Murphy's expertise is so widely respected that lawyers, judges, and policymakers from around the country retain attorney Murphy for DWI speaking engagements. Call 713-229-8333 or go online now for premier DWI defense.

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