DUI Tests, Trade Secret, & the Rights of the Accused:

Something May Have to Give

Robert J. Packard

Defense attorneys for those accused of driving under the influence of alcohol have recently begun to use a new and promising strategy for defending their clients: challenging the validity of the breathalyzer test that usually serves as the only evidence of the DUI violation.  Drivers violate the law when it can be proved that they operated a motor vehicle while their blood alcohol content (BAC) was at or above a certain level.  In most states, the proof is established by the use of a machine usually referred to as a “breathalyzer,” a machine that measures the amount of alcohol in a breath sample (supplied by the suspect) by measuring the resistance of an infrared light beam as it passes through a sample chamber containing a small amount of the driver’s breath.
Attorneys whose clients have tested for higher-than-legal blood alcohol contents have recently begun to demand the right to inspect the breathalyzer machine, including the machine’s “source code” – the computer program that runs the breathalyzer.  The rationale is that it is possible for these machines to be inaccurate, and it violates due process to convict on this evidence unless it can be properly validated by an expert witness.  And an increasing number of courts have agreed, saying that unless the prosecution can produce the source code for inspection, the breathalyzer cannot serve as evidence.  This presents a problem.  While basic rules of evidence and procedure allow the attorney of the accused to inspect a device used to gather evidence against his client, the inspection of a breathalyzer is problematic; the companies that produce these machines often refuse to produce the source code, claiming that it is protected by the doctrine of trade secret.

The Kentucky manufactured “Intoxilizer,” used by law enforcement in approximately 40 states, is at the heart of the controversy.  DUI defendants in Florida , New York , Nebraska , and elsewhere have had their charges dismissed or reduced due to the manufacturer’s refusal to release the machine’s source code for examination by the defense.  Approximately 1.5 Million DUI arrests occur each year in the U.S.

A trade secret is a property interest granted to the owner of information, whether it be a formula, program, or device, that derives economic value from remaining secret, or not being readily ascertainable by other persons who can obtain “economic value” from its disclosure.  It is an economic interest that derives its value from the fact that others do not have it, and thus cannot use it, and inasmuch as it is kept secret, its secrecy is generally afforded legal protection.  The most important factor in determining whether information can be protected by trade secret is whether the information is in fact kept secret—once made public, in other words, the protection ends.  Because the granting of protection is premised on the economic value of the secret, the protection is lost when the secret is allowed to be made public.
This fact alone makes breathalyzer manufacturers guard their source code tightly.  Besides the fact that publication can lead to a cancellation of protection, any extensive form of publication will almost certainly carry severe economic consequences.  The legal right to maintain the secrecy of the source code is crucial, because it is the fact that others do not have it that provides the economic benefit.  If the source code were released, other companies would certainly be able to use it to make competing products.
Courts, in order to accommodate the dual competing interests of intellectual property rights and fair adjudication, can attempt to devise ways for secrets to be released in litigation while still enjoying legal protection (using protective orders to limit those who review privileged material, limiting the use of the material to the particular lawsuit, sealing the court record, etc.), but too much public use of secrets makes any legal protection not only useless, but nonsensical altogether.  As the manufacturers see it, courts can make efforts to keep trade secrets from being released to the public, but where the trade secrets are demanded as evidence in an area of law that is as common, routine, and subject to a substantial degree of examination by experts as DUI, the secrecy that is the basis for the protection of the property right can easily be destroyed.  Breathalyzer manufacturers are justifiably reluctant to release the source code.
So what does this mean for prosecutors that need the source code to convict offenders and defense attorneys determined not to allow suspects to be convicted without solid evidence?  That is hard to say.  The question of how long trade secret protection should be granted to the source code of a machine that is used to convict DUI suspects is not an easy one to answer.  The man who has his license suspended wrongfully is understandably impatient with the idea that a simple examination of source code could exonerate him.  And prosecutors, while confident in the use of the breathalyzer, cannot be pleased when their sole source of evidence is thrown out of court.  The right to maintain a trade secret is strong, but it is not necessarily definite, and where courts are determined both to preserve the intellectual property rights of owners and also provide for the fair trial of the accused, efforts and concessions may have to be made by all sides.