Minnesota court affirms access to computer source code

The Minnesota State Supreme Court ruled yesterday (read the opinion here) that a person accused of driving while intoxicated is entitled to the breath test machine's source code if it can be proven that the source code could aid their defense.

Under Minn. R. Crim. P. 9.01, subd. 2(3), it was an abuse of discretion for a district court to order discovery of the source code of the Intoxilyzer 5000EN when a defendant did not submit any evidence on how the source code may relate to his guilt or innocence; however, it was not an abuse of discretion for a court to order discovery of the source code to a defendant who submitted evidence that an analysis of the source code may reveal deficiencies that could challenge the reliability of the Intoxilyzer and would relate to his guilt or innocence.

Appellant Brunner submitted a memorandum and nine exhibits to support his request for the source code. The memorandum gave various definitions of “source code.” The first exhibit was the written testimony of David Wagner, a computer science professor at the University of California in Berkeley, which explained the source code in voting machines, the source code‟s importance in finding defects and problems in those machines, and the issues surrounding the source code‟s disclosure. The next exhibits detailed Brunner‟s attempts to obtain the source code, both from the State and CMI. The last exhibit was a copy of a report prepared on behalf of the defendants in New Jersey litigation about the reliability of New Jersey‟s breath-test machine. See State v. Chun, 943 A.2d 114 (N.J. 2008). The report analyzed the New Jersey machine‟s computer source code and uncovered a variety of defects that could impact the test result. Based on Brunner‟s evidence, the district court found that the integrity of the source code is essential to the scientific reliability of the Intoxilyzer 5000EN test result. Further, the jury instructions asked the jurors to assess the reliability of the testing method, whichcould not be done without Brunner having access to the software controlling that testing process.

Minnesota uses the Intoxilyzer 5000EN which is made by CMI (the same machine used in Texas).