Freedom through Independence: Erroneous DWI Urine Test Results

Posted On May 05, 2010 by Charles Ramsay

This week we present our blog series about the value of obtaining independent tests and conducting independent analysis to reveal inaccuracies in government testing. This year alone our firm discovered cases where the Minnesota BCA has reported inaccurate DWI test results.

Yesterday, we told you how independent analysis of the state's blood sample in a case last month revealed that it was inaccurate. The BCA reported our client's blood alcohol concentration was over the legal limit of .08 and independent analysis by a local reputable lab showed it was actually .078 â?? under the legal limit.

Today our series continues with urine testing. We describe two separate cases from this year where the prosecutors agreed to dismiss charges as a result of our independent analysis of the state's sample. In one of the cases, however, the results were actually higher than what the BCA reported.


We have blogged extensively that urine testing is not generally accepted by the scientific community as a valid and reliable means of measuring impairment or determining the amount of alcohol in a person's body. That is another topic. This blog posting addresses analyses of the samples.

When a urine sample is collected for DWI prosecution, the lab must ensure the evaluation of the sample conforms to those procedures necessary to ensure the test results are valid, accurate and reliable. It appears that the Minnesota BCA does not share this view.

Eric's Urine Test Case

In January we tried Eric's urine case to jury. Before trial we had the state's urine sample analyzed by an independent lab. The Minnesota BCA had reported the urine alcohol concentration as more than .08. The independent test result was a .07, below the legal limit.

The information was sufficient to convince the prosecutor to dismiss the .08 charge. The key evidence in most DWI trials â?? the state's DWI alcohol sample â?? became irrelevant. With the critical evidence removed from the case, we easily prevailed on the impaired charge and the jury acquitted Eric. See, First Not Guilty Verdict of 2010: Hennepin County Jury Acquits Man of DWI Charges. I don't know if the outcome would have been the same without the independent analysis of Eric's urine sample.

James' Urine Test Case

While we are unaware of the precise reason for the discrepancy between test results in Eric's case, we are aware the BCA procedures are lacking as they do not ensure the test results are scientifically valid, reliable or inaccurate. For example, glucose â?? a sugar found in one's urine â?? may ferment, artificially increasing an alcohol concentration test result. Reputable labs promulgate procedures to check for glucose and avoid reporting tests that may be contaminated with the sugar.

Nationally recognized forensic scientis, Dr. Staubus, recently provided me with the State of Wisconsin's procedures it implemented to ensure test samples are not contaminated with glucose. Wisconsin, unlike Minnesota, employs significant requirements to ensure glucose does not interfere with valid and reliable test results. They include lab technicians to:

1. Check all ethanol-positive urine specimens for the presence of glucose with a Keto-diastix reagent strip. Record the Keto-diastix result on the sample submission form (implied consent specimens) or internal tracking form (MVD, death investigation specimens).

2. If a urine specimen is glucose-positive, store a room temperature for at least two days and re-analyze for ethanol concentration. If the ethanol concentration has increased by 5% or more, the ethanol result is not reported and an appropriate comment is placed on the report.

The BCA claims that because each urine kit contains sodium fluoride, it need not promulgate procedures for collection, storage and transportation of urine samples to prevent fermentation. For the same reason, it need not promulgate procedures to check for glucose.

We proved the BCA wrong. James was arrested for DWI and given a urine test. The BCA reported the alcohol result as .16. James was adamant the result could not be correct. We sent the sample to an independent lab to be retested. The independent test result was .18. The urine alcohol concentration had increased by more than 12 percent! As I explained in a previous blog post, More Issues with DWI Urine Testing: Fermentation, we demonstrated that fermentation can and does occur. Once we provided the prosecutor documentation of our independent analysis, he dismissed all the DWI charges.

In both Eric's and James' cases, we were able to prove the state's tests results were inaccurate due to independent analysis of the state's samples. We were able get the .08 DWI charges dismissed and prevailed in both cases.

Tomorrow in the final post of our four part series, we address a different method of checking the accuracy of the state's alcohol test. Unlike the previous posts where we covered independent analysis of the state's samples, we will discuss how administering an independent test at the time of arrest may provide valuable information in the defense of a DWI breath test case.

See our previous postings in the series:

Part 1: Freedom through Independence: Crises in Our Nation's Forensic Science System

Part 2: Freedom through Independence: Erroneous DWI Blood Test Results

Part 3: Freedom through Independence: Erroneous DWI Urine Test Results

Part 4: Freedom through Independence: Erroneous DWI Intoxilyzer 5000 Breath Test Results