Friday, November 12, 2010

More developments on defence access to breathalyser source code

I've blogged before about whether a defendant in a drink driving charge is entitled to examine the source code to the breath testing machine, and there's been a High Court decision on this point since then, but this issue has recently cropped up yet again in the form of an interesting decision of the Information Commissioner.

In Case 080260 - Mr. W & The Medical Bureau of Road Safety (MBRS) the applicant sought to use a FOI request to the Medical Bureau of Road Safety to obtain (amongst other things) the source code relating to a "Lion Intoxilyzer 6000 IRL". The decision of the Information Commissioner addressed a number of important issues - including whether FOI could be used to "provide a parallel system whereby the defence could obtain what is in effect disclosure in a criminal case" - but in relation to the source code the Commissioner had this to say:
It is my understanding that the term "source code" refers to high level code, the disclosure of which would allow the development of competing products. I therefore accept that the source code at issue in this case qualifies as a trade secret within the meaning of section 27(1)(a) of the FOI Act. I also consider that, on balance, the public interest would not favour release, particularly if the testing, maintenance and repair records are made available. As Ms. Campbell stated, court procedures must be considered adequate to ensure the fairness of any criminal proceedings under the Road Traffic Acts.

I also accept that a duty of confidence would be owed to Lion Laboratories in the circumstances. Moreover, I note that evidence was submitted in the case stated by Judge Mary Devins in DPP v. O'Malley [2008] IEHC 117 to show that the MBRS is contractually prohibited from disclosing the source code to any third party. In the circumstances, I am satisfied that the source code is exempt under section 26(1)(b) as well as section 27(1)(a) of the FOI Act.
While this may be the correct result in the context of FOI, when taken together with the decision in DPP v. O'Malley it seems to leave defendants in drink driving cases with no effective means of challenging the inner workings of the machines used to convict them, and may potentially lead to an injustice. As a fundamental principle of law, if a person is to be convicted based on the "testimony" of a machine then that person should have the right to challenge the process by which the machine generates that "testimony" - something which may require inspection of the source code. As things stand however it seems that there's no route in Irish law for that to be done.


  1. If a defendant was entitled to view the source code in a breathalyser, would it extend that a defendant in any trial involving technology could seek access to the source code of a relevant device? This would seem very open ended?

  2. Under Irish law a defendant can already seek access to inspect the physical apparatus of the breathalyser - but experience has shown that the courts can and will prevent this jurisdiction from being abused. Inspecting the source code - the logical apparatus - wouldn't appear to pose any greater risk of abuse.