Questionable Lab Results in DUI Cases Challenged

The accuracy of blood-testing equipment used by Scottsdale police in DUI cases has recently come under intense scrutiny. In fact, hundreds of DUI cases from the past four years could be called into question if the legal challenge is successful. This could also affect the treatment of forensic evidence in courts throughout Arizona.

Eleven felony DUI cases have been consolidated into an ongoing evidentiary hearing in Superior Court, all of which involving serious DUI allegations. At least two of the suspects submitted themselves to preliminary breath tests, and their blood-alcohol content registered more than 0.20 percent, more than twice the legal limit. At least eight of the suspects had prior DUI convictions.

Scottsdale police have been aware of potential problems with the blood-testing equipment for years. For example, the equipment mislabeled vials with wrong names or numbers, quit running during tests and erased baseline information from measurements during test runs.

The question is whether a crime lab technician’s decision to use old software on a new blood-testing machine in 2009 has affected evidence handled by Scottsdale’s crime lab. Scottsdale police maintain that the lab has been accredited since 1996 because its practices for maintaining equipment meet or exceed national standards, a belief not shared by most defense attorneys. By the following summer, the supervisor determined the old software was incompatible because half of the information on the reports was nearly impossible to interpret accurately. The machine’s manufacturer sent a technician to install a patch but said it would not be liable for problems with the software. The supervisor later testified that the patch did not fix the problem. However, according to a forensic scientist with the crime lab, the manufacturer refused to exchange the machine.

According to a published report from the Governor’s Office of Highway Safety, Scottsdale police issued citations for more than 2,500 DUIs last year. Approximately 150 of those were the type of felony DUIs that end up in Maricopa County Superior Court. The vast majority go to Scottsdale City Court, where attorneys say most judges don’t even let juries hear information about potential problems with crime-lab evidence.

Any criminal defense attorney will argue that this deliberate omission presents a serious problem as they try to defend their client. It goes beyond suppressing evidence. Juries are kept in the dark about potential inaccuracy in lab testing to determine blood alcohol content. Clearly, this results in a much higher conviction rate.