Posted On April 07, 2008 by Charles Ramsay


In 2006 33,942 drivers were tested by 200 Intoxilyzers breath test machines in Minnesota. See the Minnesota Bureau of Criminal Apprehension's 2006 Annual Report. The Intoxilyzer 5000EN is manufactured by CMI, located in Kentucky.

All of today's breath test machines are run by a computer and software runs the computer. The software is represented by source code (set of procedures and instructions that run the computer) and is translated into machine language and stored in the Electronic Programmable Read Only Memory (EPROM).

The Intoxilyzer's computer utilizes the Z-80 microprocessor - the 1970s era chip that ran the Radio Shack's Tandy Z-80 computer. The EPROM handles all of the machine's primary functions. An integrated circuit combines a clock, calendar, volatile memory and backup battery. The battery maintains the data generated of all tests until the BCA downloads the data via modem to a host computer for long term storage. The software stored in the chip is responsible for ensuring proper administration of the test, including operation of the scientifically required safeguards necessary to ensure the test results are valid, accurate and reliable.

All new software has bugs. Although software engineers use patches and updates to correct the problems, errors begin to develop. This may lead to invalid, erroneous or unreliable results. In the world of DWI breath testing, even a tiny error may determine whether drivers lose their license, their vehicle or their freedom.

Defense attorneys around the country are challenging the validity of breath test results by focusing on the source code. Claiming that courts treat the machine as a magic box, many are seeking the source code to determine if it runs the machine with the necessary safeguards while performing as the government and manufacturers claim.

The following analysis is based on Minnesota law and procedure.

Rules of Discovery

Criminal - Misdemeanor

Rule 7.04 of the Minnesota Rules of Criminal Procedure governs discovery of misdemeanor DWI prosecutions. Under the rule, defendant are entitled to a copy of police reports; all other discovery is available by the agreement of the parties or order of the court. Minn. R. Crim. P. 7.04 & cmt. The comments to rule 7.04 direct the court to rule 9 when determining whether to order any additional discovery. Because the rules governing discovery of additional information in misdemeanor DWI prosecutions are identical to those in gross misdemeanor and felony prosecutions, the issues will be addressed below.

Criminal - Gross Misdemeanor & Felony

Rule 9 of the Minnesota Rules of Criminal Procedure governs discovery in gross misdemeanor and felony cases. The rule requires the prosecutor to provide the defendant with access "to all matters within the prosecuting attorney's possession or control which relate to the case" and to "disclose and permit defense counsel to inspect and reproduce books, grand jury minutes or transcripts, law enforcement officer reports, reports on prospective jurors, papers, documents, photographs and tangible objects which relate to the case." Minn. R. Crim. P. 9.01, subd. 1(3). The prosecutor must also disclose to the defendant any evidence "that tends to negate or reduce the guilt of the accused." Minn. R. Crim. P. 9.01, subd. 1(6).

In addition to the material that the prosecutor must disclose, the defendant may move the court to order additional discovery of "any relevant material and information not subject to disclosure without order of court under Rule 9.01, subd. 1." Minn. R. Crim. P. 9.01, subd. 2(3). The defendant's motion must be supported by a showing that the material or information sought "may relate to the guilt or innocence of the defendant or negate the guilt or reduce the culpability of the defendant as to the offense charged." Id.

Whether the source code is available to the defendant in a DWI prosecution turns on the district court's determination of relevance and discoverability. Defendants seeking discovery of the Intoxilyzer source code must show that the source code relates to the defendant's guilt or innocence or can negate the defendant's guilt. Even if the defendant makes a showing of relevance, the prosecutor may preclude discovery by showing that the source code is not discoverable or not within the possession or control of any governmental agency. Minn. R. Crim. P. 9.01, subd. 2(1), subd. 3. This is a hotly debated topic.

Civil - Implied Consent

When a driver petitions for judicial review of a license revocation, the Commissioner of Public Safety is required to provide the driver with notice of the license revocation, the test record, the police officer's certificate and any accompanying documentation from the arrest, and disclose any potential witnesses. Minn. Stat. § 169A.53, subd. 2(d)(l)-(4). Any additional discovery is only available through order of the court. Id. Because implied consent hearings are civil hearings, the rules of civil procedure apply. The driver may move the district court to order discovery of "any matter, not privileged, which is relevant to the subject matter involved in the pending action." Minn. R. Civ. P. 26.02(a). The discovery sought need not be admissible at trial as long it is reasonably calculated to lead to admissible evidence. Id.

Discovery of the source code in an implied consent hearing turns on the district court's determination the source code is relevant to the grounds for the license revocation. The discovery rule in civil proceedings is sufficiently broad to allow discovery of inadmissible information, as long as the party seeking the information can show that it might reasonably lead to admissible evidence. If the petitioner's license was revoked after a failed breath test, then the petitioner is specifically entitled to challenge the validity of the breath test under Minn. Stat. § 169.53, subd. 3(10). Because the source code determines how the Intoxilyzer collects and processes the driver's breath sample, any irregularities or shortcomings in the source code could render the test results invalid.

In re Commissioner of Public Safety (Underdahl)

The Minnesota Supreme Court addressed the source code issue last summer in In re Commissioner of Public Safety, 735 N.W.2d 736 (Minn. 2007) (Underdahl). In Underdahl, the district court ordered the commissioner to provide the petitioner with the Intoxilyzer source code. Id. at 709. The commissioner then petitioned the court of appeals for a writ of prohibition to prevent the district court from enforcing its discovery order. Id. The court of appeals denied the commissioner's petition. Id.

The supreme court first considered the commissioner's argument that a writ of prohibition is appropriate because the district court lacked jurisdiction to order discovery of the source code in light of the presumptive reliability of the Intoxilyzer test results. Id. at 711. The supreme court rejected this argument, noting that the petitioner in an implied consent hearing is explicitly entitled to challenge the reliability and accuracy of the breath test results despite the statutory presumption. Id.

The supreme court also considered whether the district court's order was an abuse of discretion. Id. In light of the district court's wide discretion to issue discovery orders" and the liberal construction afforded to the remedial discovery rules, the supreme court addressed the commissioner's other argument that the source code is "not discoverable." Id. at 712. The commissioner argued that it did not have possession, ownership, or control over the source code and that it did not have an adequate remedy at law. Id. The supreme court noted that the record was not sufficient to determine the federal copyright issues raised by the commissioner and that the commissioner failed to demonstrate a lack of legal remedy. Id. at 713.

Ultimately, the supreme court affirmed the denial of the writ of prohibition, determining that the commissioner failed to show that circumstances justifying the issuance of a writ of prohibition were present. Id.

District Court Rulings - What Is The Standard? Who Has Burden?

Defense attorneys have brought motions seeking orders for the production of the source code in hundreds of implied consent and criminal proceedings. The drivers' attorneys and government attorneys have a significant difference of opinion regarding the standard for production of the source code.

Government's Position:

The government typically argues that a driver is not entitled to the source code as (1) the state does not have custody, possession and control of the source code, (2) the driver cannot demonstrate a "need" for the materials and (3) due process does not require production. Even if discovery is ordered, the state typically requests a protective order to ensure CMI's interests are protected.

Although a very small number of attorneys have signed CMI's proposed order, CMI has yet to produce the source code.

Driver's Position:

In criminal cases defense attorneys are arguing that "Criminal defendants have a broad right to discovery and to prepare and present their defense." Many note that the rules of criminal procedure provide for discovery of "all matters within the prosecuting attorney's possession or control which relate to the case," and specifically any evidence "that tends to negate or reduce the guilt of the accused."

Most defendants counter the state's position by claiming the software is relevant, is within the state's control, the evidence sought is not available by any other means, and due process requires production of the materials.

These issues will not be resolved soon. Only two criminal cases are currently pending before the court of appeals and with no civil implied consent cases on appeal.


Some attorneys have signed the agreement proposed by CMI and have also paid for a copy of what is purported to be a paper copy of "the source code." A representative of the Minnesota Attorney General, represented in a telephone conversation in an October, 2007 telephone conversation that CMI intends to disclose "the source code," but must reverse engineer the machine language to obtain the code, and it would be ready in a matter of days.

The Minnesota AG's office had made representations of imminent disclosure before that conversation and continues to claim that CMI will disclose the material "tomorrow" or "by the end of the day."

CMI has disclosed nothing, despite a few Minnesota attorneys' ill-advised actions, i.e., signing non-disclosure agreement, paying for a paper copy of what is purported to be "the source code."

The Minnesota Society of Criminal Justice (MSCJ) is attempting to coordinate the efforts and resources of the attorneys involved in this litigation. Many attorneys who do not regularly practice in this area a jumping on the bandwagon and setting bad precedent.

My concern is unsuspecting Minnesota attorneys will find themselves in the position of the proverbial dog who actually catches the car. Without the teamwork, expertise and effort displayed by the courageous New Jersey lawyers in Chun, I am concerned a Minnesota lawyer may obtain something less than the full source code.

If the attorney were to hire an "expert" to perform a cursory review and find nothing of value, CMI would tout this as a victory and try to leverage the lack of findings to prevent not only further disclosure in Minnesota, but may also use the precedent to shut down full disclosure in other states as well.

On March 3, 2008 the Minnesota Attorney General filed suit against CMI to enforce the contract seeking the source code. Two young bright attorneys from the gambling & implied consent section of the office are litigating the matter. CMI has requested an extension to serve an Answer to the Complaint. The AG granted the request. I have yet to see the answer.

And Just Recently ... A Kentucky Court ordered CMI to turn over the source code to a defendant in Kentucky. The court noted that the software was relevant and production would not be unduly burdensom; the source code could be copied to cd-rom disk for less than a buck!

See Kentucky Lawyer's, Stephen J. Isaacs Blog.


See more from the Minnesota Lawyer Blog (Minnesota Lawyer newspaper):

Minnesota Lawyer Blog: Source code dispute puts convictions in jeopardy

Charles A. Ramsay

Attorney at Law


450 Rosedale Towers

1700 West Highway 36

Roseville, MN 55113

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