Plano DWI Lawyer Blog

The Intoxilzyer 5000 is the breath testing device used by the police in Texas to capture a DWI suspect's breath. The device purports to measure a person's alcohol concentration in breath, and express it in terms of grams of alcohol per 210 liters of breath. 

Recently, I posted about how the manufacturer of the Intoxilyzer 5000 refuses to allow any outside entity to view its source code. It appears that the bad news for the Intoxilyzer continues to accumulate.

In Virginia, an attorney learned that the state purchased replacement motor for the chopper wheel, a component of the Intoxilyzer 5000 that filters the infrared red energy absorbed by  a DWI suspect's breath sample after the infrared energy passes through a portion of the device known as the sample chamber.

The fact that Virginia replaced the original motor with parts from random companies is a problem, because the replacement motors may spin the chopper wheel at an RPM that is too fast. This accelerated speed may affect the complex calculations being performed, which may in turn affect the breath test result reached by the machine.

What else don't we know about the Intoxiyzer 5000? How do we know that Texas has not done the same thing with its machines? 

In Texas Driving While Intoxicated (DWI) cases , a machine called the Intoxilyzer 5000 is the device used by police to take a sample of your breath to measure alcohol concentration. The Intoxilyzer 5000 is one in a series of breath testing devices manufactured by the CMI corporation of Kentucky.

The device employs a software program to measure the alcohol concentration and the manufacturer has steadfastly resisted efforts to disclose the Intoxilyzer's source code. Perhaps that resistance is slowly being overcome. In a series of cases Judges in Arizona, Minnesota, Kentucky and Florida have ordered that CMI turn over its source code to attorneys representing clients in Driving While Intoxicated cases. CMI claims that the source code material is proprietary.

Essentially, everyday in this country people are convicted on the basis of the results of a machine whose software has never been subject to analysis, independent scrutiny, or even view by those who will suffer because of its results.

It is a constitutional right in this country to confront one's accuser in court as well as to know the evidence against one. Perhaps the time is right for Texas DWI defense lawyers to seek to compel disclosure of the source code for the Intoxilyzer 5000.