The Missouri Highway Patrol recently issued instructions to its troopers indicating blood evidence, such as a blood draw from a DUI arrest, does not need to be refrigerated. This is a puzzling announcement, as there are typically concerns that blood samples held at room temperature could lead to a compromise in quality and make the evidence worthless, or worse.

An email sent out to its troopers stated, “neither the forensic handbook nor patrol policy requires the refrigeration of a blood sample.” Blood evidence is typically refrigerated to prevent sugars in the blood from fermenting and creating ethanol, a form of alcohol. Such fermentation could alter the alcohol content of the blood, and provide a false reading of a suspect’s blood alcohol content (BAC).

The Missouri Department of Public Safety confirmed that this new protocol is correct and it claimed that they had a study that found that unrefrigerated blood samples did not develop increased alcohol concentrations due to fermentation.

It is unclear the veracity of the claimed studies the Highway Patrol is relying on, but a publication from National Institute of Standards and Technology entitled “The Biological Evidence Preservation Handbook: Best Practices for Evidence Handlers” from April 2013, notes that refrigeration of liquid blood evidence is the only recommended storage procedure.

Why the Highway Patrol would make such a pronouncement, as seemingly opens any DUI case to questions of the quality of the evidence. DUI cases, like all criminal cases, place a high burden on the prosecution to prove guilt beyond a reasonable doubt and handling evidence in a manner that could compromise its testimonial value is puzzling.

Source: fox2now.com, “Some question new way MO Highway Patrol gathers drunk driving evidence,” Chris Hayes, May 9, 2016