Phoenix Moving to Blood Test for DUI Suspects

Phoenix sets 2010 as date to use blood tests for Arizona DUI arrests.

Phoenix has joined other Arizona cities in the movement to rely on blood tests to identify drunk driving suspects. Advocates say that blood tests are more accurate than breath tests for determining blood alcohol content. The Phoenix Police Department has set a date of 2010 to accept only blood based evidence in DUI court cases.

Arizona DUI defense attorneys have long argued the problems associated with breath samples for determining a legal threshold in drunk driving cases. Aside from equipment calibration and maintenance issues, discrepancies in readings can occur through incorrect administration of the test. As recently as the year 2000, nearly 1,400 Arizona DUI cases were dismissed in Phoenix and Glendale alone due to legal challenges to the machine results. To complicate the issue, a new Arizona law requires the installation of an ignition interlock device for everyone convicted of DUI, even first time offenders. With the consequences so high, the need for accuracy becomes even more important.

While both blood and breath tests can gauge a motorist’s blood-alcohol concentration, breath testing equipment has been the norm for identifying drunk drivers because of portability and immediate results.

Mesa has been using blood evidence for almost ten years. Scottsdale, Chandler and Peoria police departments also collect blood samples in DUI cases. Phoenix became able to process large numbers of blood samples after the opening of its new crime lab earlier this year. About 40 percent of the Phoenix police precincts have transitioned from breath to blood tests since last March.

Blood evidence will be collected at the precinct or by an officer in the field. Though officers must complete training in blood drawing, defense attorneys say it is not the same as a hospital environment with health professionals. Subsequently, the results can be compromised depending on how and when the samples are collected and how they are handled.

In addition, the actual blood is not tested to determine blood alcohol content. A machine reads the alcohol molecules in the air above the blood, leading to another potentially subjective interpretation.