Under limited circumstances, the answer is yes.

Breathalyzer results on a properly certified machine are nearly always admissible at trial.  However, results from a portable breathalyzer are not considered reliable and are generally not permitted. The breathalyzer taken on the street when you were arrested is almost never admitted as evidence.

But there is one exception. The state has a new weapon that they can use in certain circumstances. The trial judge may allow the state to use the results of a portable breathalyzer that has an attached printer.  Bear in mind that portable breathalyzers still come with a wide range of problems that simply adding a printer will not solve.

If the state does try to use a portable breathalyzer against you, you may be able to hire an expert witness to shed doubt on the reliability of that evidence.  Portable breathalyzers can notoriously pick up mouth alcohol (such as a liquor that might stick to your teeth), and they also can be radically thrown off if you blow too hard into them.

While an expert is expensive, the potential personal and professional perils of picking up a DUI conviction may well outweigh the cost.  An expert does not automatically mean that a judge or jury will disregard a portable breathalyzer, but an expert may still make a dramatic difference in the outcome of your trial.

If you have been charged with a DUI or similar offense, contact an experienced attorney immediately.  An attorney can review your case for its best possible defense.  As with most crimes, the state must prove all the elements beyond a reasonable doubt.  An experienced DUI attorney may be able to show that the state’s evidence is shakier than they would like a judge or jury to believe.

If you have questions about this or another related Illinois criminal or traffic matter, please contact Matt Keenan at 847-568-0160 or email

(Besides Skokie, Matt Keenan also serves the communities of Arlington Heights, Chicago, Deerfield, Des Plaines, Evanston, Glenview, Morton Grove, Mount Prospect, Niles, Northbrook, Park Ridge, Rolling Meadows, Wilmette and Winnetka.)


About mdkeenan

A criminal and school law attorney with over 17 years of experience, I have successfully represented clients all over the Chicago area. My practice includes DUI, felony, criminal, misdemeanor, homicide, internet crime, retail theft, traffic offenses, cyberstalking, drug crimes, weapons violations, domestic battery and juvenile crime. I also represent families involving school cases. My clients come from all over the Chicago area including Skokie, Wilmette, Niles, Northbrook, Glenview, Evanston, Winnetka, Highland park, Northfield, Park Ridge, Des Plaines and Mount Prospect. I am a member of the ACLU and the Illinois State Bar Association. I serve as a volunteer for First Defense Legal Aid. Se habla espanol.
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