extreme chandler DUI - entrance to the court house

Defenses Against DUI: Part 4

It is important to understand that there are many ways to defend extreme DUI charges. There are a number of constitutional and statutory challenges that attorney Todd Coolidge looks for when he prepares a DUI defense.

The main piece of evidence used by the State during a DUI case is the chemical test. The blood test is usually conducted on a Gas Chromatograph while a breath test is usually administered using an Intoxilyzer.

Both of these types of tests are conducted using a machine and there are a number of rules and regulations that govern the use of these machines. There are also a number of factors that can affect the results these machines produce.


Some of the errors associated with an Intoxilyzer (breath) test are:

  • Range of Error
  • Variables for the instrument, such as breath patterns, body temperature of the accused, and blood to breath partition ratio
  • Operator Error
  • Mouth alcohol
  • Radio frequency interference


The Intoxilyzer is a machine that has to be calibrated every 30 days, and tested every 90 days to make sure it can catch some of the issues listed above. A thorough investigation of the calibration records and standard quality assurance records is necessary in order to show that the machine is functioning properly and accurately.

Attorney Todd Coolidge, recognizes the distress and difficulty that come with criminal charges such as an extreme DUI. With a convenient location in Chandler, our services are available to all of the residents of the metro Phoenix area (including Scottsdale and Paradise Valley), as well as throughout the state of Arizona, who wish to have their rights protected. Contact us today for a prompt response from our qualified law team to begin your path to a strong defense