A recent Missouri Supreme Court ruling has cast a shadow on DWI cases involving the use of breath analyzers between December 2012 and February 2014. Thousands of cases may be impacted.

The case highlights a 14-month loophole that changed how breath analyzers are calibrated. The machines are expected to be calibrated every 35 days to ensure they are working correctly.

That was not the case for Kristin Stiers. Stiers was suspected of driving while intoxicated and stopped in 2013 by Lake St. Louis Police. The state high court ruled that the machine used by the police was improperly calibrated and the results of Stiers’ breath test be excluded from evidence. The court said her driving privileges should be reinstated.

The Missouri Department of Health and Senior Services regulates breath analyzers. However, due to changed wording in their regulations on maintaining the machine, a loophole was created between December 2012 and February 2014. During that period, the regulation wording used the word “and” instead of “or.” This slight word change instantly required police to conduct three calibration tests instead of just one. The machines now needed to be verified and calibrated with a .04, a .08, and a 0.10, and remained that way until February 28, 2014. In Stiers’ case, the machine was calibrated at only one level.

Several thousand people are estimated to have been pulled over for a DWI during this 14-month period. The Supreme Court case is Kristin Nicole Stiers vs. Director of Revenue.