Breathalyzer Test

In a DUI-DWI case, two general types of a DUI breathalyzer test may have been offered to you.  The first may have been a preliminary, roadside, hand-held field breath analyzer that typically runs off a 9-volt battery.  Some devices can also run from a power cord that inserts into the police car’s cigarette lighter. The other may have been a more scientific machine (like an Intoxilyzer®, a BAC Datamaster®, an Intoximeter® or a Draeger®).  The roadside test is the handheld device, which an officer can use like other field sobriety tests in his or her quest for enough DUI police evidence to be able to arrest you. 


All states will allow the use of these breathalyzer devices to test you if you consent to being screened.  In almost all states, since the screening tests at the roadway are non-evidential, you may decline taking the field breathalyzer without any penalty.  Further, in the overwhelming majority of states, the battery-powered devices are only allowed to determine the presence of or absence of alcohol in your system.  Other states allow the officer to disclose the number from such portable screening breathalyzers to the jury at trial and to guess at your possible level of physical impairment due to the “number” reported on the breathalyzer device.   


Some states have specifically declared the use of these hand-held devices to be a part of their DUI implied consent law.  Due to the lack of regular calibration checks for accuracy on these devices, any numerical values on the machine at the time of your testing are legally irrelevant in most states except for establishing the presence or absence of alcohol on your breath.


The more sophisticated and more scientifically dependable EVIDENTIAL breath test is the machine used at the police station or at the jail (like an Intoxilyzer®, a BAC Datamaster®, an Intoximeter® or a Draeger®). These are usually table-top machines that plug into a 110-volt outlet and produce a print-out of the results after the testing.  Some jurisdictions have purchased mobile testing vans that may contain these devices inside.  Several of the major breath testing manufacturers sell these portable devices in both evidential models and non-evidential versions.  The rest of this subsection deals with these machines, inasmuch as the numbers produced by these devices are the results that can be used against you in a typical court case as evidence by the prosecutor to establish your actual blood (or breath) alcohol level at the time of your arrest.


A new movement is occurring with all of the major breath testing machine manufacturers to make the evidential testing devices portable. Then, an officer can test you immediately at the roadside with a full-fledged, evidential (meaning, that the printed result can be used in court) breath analyzer that prints out a test card for later use against you at trial.  In many states, non-evidential, hand-held roadside testers are allowed for use by officers, but any results observed on the digital readout are not admissible in court.


Any experienced DUI-DWI specialist either has his or her own breath testing devices that can be used to run experiments, or has access to the breathalyzer machine used in your state through one or more expert witnesses.  These devices are subject to giving false high readings due to a variety of problems with the machines, including the presence of common items such as the residue of peppermint Altoids®, pizza (especially with onions), carbonated soda containing fruit flavoring and sugar (such as Sprite®) or even white bread in your mouth. 

Our veteran DUI lawyers file pre-trial motions to exclude breathalyzer results from being introduced as police evidence in your DUI trial. Many ways exist to exclude breathalyzer results, and an exclusion can lead to a favorable case outcome.