DWI Technology

Law enforcement may be equipped with a wide range of technologies to help them arrest drivers suspected of driving while intoxicated (DWI). They are used to,

  • Indicate if a driver is intoxicated,
  • Measure the driver’s blood alcohol content (BAC), and
  • Prevent an intoxicated driver from starting or driving a vehicle.

No technology is perfect. The officer using it may make mistakes so the results may be challenged in court, depending on the circumstances.

Breathalyzer: Alcohol consumed by a driver is absorbed into the body and some of it is exhaled out.  This device is supposed to detect alcohol in exhaled breath then calculate the person’s blood alcohol content (BAC). Breath samples are not saved and cannot be independently checked again. To be accurate and the findings admissible in court, Breathalyzers need to be calibrated, maintained and the officer using it properly trained.

Blood test: This should be more reliable than breath testing, but blood samples may be contaminated or mishandled. Blood samples should be saved. They could be re-tested by a lab hired by a defense attorney. A finding in a second test that the BAC is less than 0.08% (the percentage where a driver is considered intoxicated) could be used to show the defendant is innocent of a DWI charge.

Alcohol-sensing flashlights: They look like ordinary flashlights but they have sensors that are supposed to detect alcohol on a person’s breath within a foot of a person’s face. They can’t determine a driver’s BAC but if the sensors show alcohol use, it may result in an officer requesting the driver submit to a breathalyzer or blood test.

Ignition interlock device: This device could be part of sentencing for a DWI conviction. It’s a breathalyzer type device connected to the vehicle’s ignition. The driver blows into the device and if it determines the driver isn’t intoxicated, the engine should start. If the results are the person is intoxicated, the engine should not.

Continuous alcohol monitoring: An electronic ankle bracelet has a transdermal alcohol sensor which detects alcohol in the wearer and transmits that information to a remote sensor. This could be used like an ignition interlock system.

If you have any questions about DWI technology, or you’ve been arrested for DWI and want to learn more about how they can be used and challenged in court, contact us to speak to a DWI defense lawyer today.