• 18
  • April
    2011

At the end of March, we wrote a post regarding mistakes Pennsylvania police made in more than 1,100 DUI arrests in Philadelphia. After an attorney challenged the results from a breathalyzer, the police checked the calibration of the eight breathalyzers used by the city. Five of the machines were not calibrated correctly, and the mistake was linked to more than 1,100 Pennsylvania DUI arrests.

Perhaps the most frustrating element of the entire situation is the cause of the errors. There was nothing wrong with the Intoxilyzers when they were used to give breath tests to individuals suspected of drunk driving.

The only mistake was human error.

Although the Pennsylvania police originally thought there could be mistakes in the 1,100 DUI arrests associated with the five machines, they are no longer even certain of that. The error the police made was in failing to certify whether the machines were calibrated.

One scientist used the following analogy: "If you don't have an inspection sticker, it doesn't mean that the car is bad. It just means that you can't verify that the car is working correctly."

The Intoxilyzer works - or fails - because of numerous spectrometers. A spectrometer measures a given element based on a pre-determined base number. To ensure the Intoxilyzer is measuring elements against the proper scale, it needs to be calibrated frequently. Every Intoxilyzer has a drift, so regular calibration is necessary to ensure proper readings.

When a mistake is discovered while the machines are being calibrated, the machines are not supposed to be used until the mistake is fixed. That is where Philadelphia went wrong. Even after realizing the machines did not meet the standard, they were still used.

Read more in the next post to learn about similar errors reported in other states, as well as the steps Pennsylvania is taking to rectify the situation.

Source: Philadelphia Inquirer, "Operator error in breath tests?" Don Sapatkin, 4 April 2011