Missouri DWI from "Alcohol & Drugs Combined" very different than "Alcohol Only DWI"

Yes, you can have an alcohol BAC below the legal limit of .08 and still be charged with DWI, especially if the arresting officer claims you had drugs in your system. You can be charged with alcohol/drugs combined based solely on observations of the police officer, even if you refuse to take a breath test, urine test, or blood test. Obviously, positive test results for drugs through urine or blood make the case stronger, but are not required to write the ticket or file the charges. However, the fewer test results they have the better chance we have at beating the charges.

Our DWI lawyers recently got a DWI Alcohol/Drugs charge dismissed. The driver had alcohol content of .04 (below the legal limit of .08) but tested positive for XLR-11 or synthetic marijuana. A basis of any DWI charge is that the State must prove that the  driver was “impaired”. The presence of drugs in someones system does not always mean it impaired them. The amounts in their system must be quantified, meaning presence alone is not enough, they must show how much and that the amount caused impairment.

In this case the Missouri highway Patrol’s laboratory results only showed that XLR-11 (synthetic marijuana) was in the driver’s system, not how much or if there was enough to impair the driver. The defense was broken down as follows to get the alcohol/drugs charge dropped:

Defeating the Alcohol part of the DWI:

After the traffic stop, the arresting officer, Trooper Harms, recorded some parts of the “Field Sobriety Test” (performed at the roadside at night under conditions of “strong wind gusts”), which reflected his suspicion for impaired driving by the driver. The “Field Sobriety Test” has not been scientifically validated and contains numerous subjective assessments by the arresting officer. It serves only to document the arresting officer’s suspicion. It is not proof of intoxication, and it requires objective laboratory testing to determine the presence and quantity of alcohol (if present).

Trooper Harms also recorded a “Positive Breath Test”, which can only be interpreted as a qualitative (but not quantitative) test, and it likewise requires objective testing. The police report does not state the device used for the “positive breath test”, the form of the result, or the calibration and maintenance history of the device.

The driver had blood drawn at St. Joseph’s Hospital at the order of the arresting officer. Blood drawn at 2320 hrs (80 minutes after the arrest) yielded a whole blood alcohol concentration of 0.040%. A second sample obtained 30 minutes later at 2350 yielded a blood alcohol concentration of 0.032%. These two values are well below the statutory limit of 0.080%. Together these two values establish Mr. Decker’s elimination rate for alcohol. A decline of 0.008% over 30 minutes gives an elimination rate of 0.016%/ per hour.

Humans eliminate alcohol at a constant and linear rate (zero order kinetics) and metabolize the same quantity of alcohol for each interval of time after the peak concentration. Mr. Decker’s elimination rate of 0.016% per hour is in the expected range of 0.015 to 0.020% per hour for people who are not alcoholics. Ignoring the possibility that at the time of the arrest the driver could still have been absorbing recently ingested alcohol and could have reached his peak blood alcohol concentration sometime between the time of the arrest and the first blood draw, one can back-calculate his blood alcohol concentration using this elimination rate:

80 minutes = 1-1/3 hours or 1.33 hours

1.33 hours x 0.016 % per hour = 0.021% (change in BAC from the arrest to first blood draw)

0.021% + 0.040% = 0.061% (BAC at time of arrest) Therefore, the driver’s  BAC at the time of the arrest was well below the legal limit of 0.080%.

Defeating the “Drugs” part of the DWI – XLR-11 or Synthetic Marijuana

Teh driver’s blood was tested by Gas Chromatography / Mass Spectroscopy (GC/MS) for known drugs of abuse. The GC/MS performed by the MSHP Forensic Laboratory was negative, but the MSHP Forensic Laboratory did not measure newer synthetic cannabinoids. The blood sample was then sent to National Medical Laboratories (NMS) in Willow Grove, PA for synthetic cannabinoid testing, which revealed a qualitatively positive test only for the presence of XLR-11 with no concentration reported.

XLR-11 is a synthetic chemical, (1-(5-fluoropentyl)-1H indole-3-yl) 2,2,3,3 tetramethylcyclopropyl methanone, that is believed to act at the CB1 and CB2 receptors in the brain. It has been marketed on the internet as a legal alternative to marijuana.

The exact physiological role of the CB1 and CB2 receptors in humans remains poorly and incompletely understood. XLR-11 has never been systematically studied in humans, so there is no reliable information that relates the use of XLR-11 or a specific blood concentration of XLR-11 to specific physical effects that may impair driving.

Self-reports by users posting their experiences on the internet have suggested the following possible effects:

“Positive Effects: You may feel happy and relaxed. You may get the giggles. You can feel hunger pangs and become very talkative. Some other people get more drowsy. State of mind and recognition can change. Concentration and co-ordination may become heavy.

Negative Effects: Paranoia, panic attacks, forgetfulness, spew up, rapid heartbeat, disorientation, lack of physical coordination, depression, sleepiness.”

The observations reported by Trooper Harms in the DWI arrest report and in his accompanying narrative do not clearly illustrate any of these effects which might be attributable recent use of XLR-11. Neither the subjective “field sobriety test” performed by the arresting officer at night under adverse weather conditions nor the subsequent testing of the driver’s blood and property demonstrate intoxication or impairment by XLR-11. The evidence only conclusively demonstrates the possession of XLR-11 and recent exposure to XLR-11 at the time of the arrest.

Detection of XLR-11 in samples submitted to NMS began to appear in late 2012 and increased in early 2013 (coinciding with the date of the driver’s arrest on 9 February 2013. At the time of the arrest, the possession or use of XLR-11 was not prohibited by Missouri or Federal laws. On 12 April 2013, over two months after the driver’s arrest, the DEA issued a notice of intent to include XLR-11 among the list of prohibited substances named in the Federal Register, and this became effective on 16 May 2013 (over three months after Mr. Decker’s arrest).


  1. At the time the single observed lane drift and his immediately ensuing arrest, the driver had an estimated blood alcohol concentration of 0.061% (well below the statutory limit).
  2. The presence of XLR-11 among the driver’s personal property and the qualitative detection of some XLR-11 in the driver’s blood only confirm possession (before the substance was banned) and recent exposure with no evidence of intoxication or impairment attributable to XLR-11.