• Stephen Biss

How do I defend my impaired driving charge?

How does a lawyer defend an impaired driving, DUI, or over 80 charge?

Please don't assume that defending an impaired driving charge is impossible. Although the police officer who charged you with impaired driving may have been courteous and thorough, he or she may have made some mistakes that can be discovered by a very experienced impaired driving defence lawyer.

Impaired driving is considered a serious criminal offence in Ontario. Police generally use good quality equipment and procedures in investigation of impaired driving charges. However, good equipment is not infallible in the prosecution of impaired driving charges. If police don't follow exact protocol and standards on the ASD or the Intoxilyzer, then you may be able to raise a real doubt that the breath tests were not scientifically reliable.

Unfortunately most impaired driving lawyers never travel beyond conventional defences. A successful impaired driving defence often involves raising unconventional issues. This site encourages defence lawyers to be more adventurous and hopefully raises the bar for impaired driving defence while at the same time encouraging respect for scientific method in forensic science.

An impaired driving lawyer with a great deal of experience in raising Charter of Rights defences can carefully analyze the disclosure and identify police errors which may result in exclusion of evidence of impaired driving or over 80, thus resulting in an acquittal. A lawyer who challenges the conventional wisdom of impaired driving science can cross-examine the qualified technician or Crown forensic scientist to expose breaches of protocol or malfunction.

The starting point for any impaired driving defence is a careful review of everything you recall about your interaction with the police using a resource such as the Canadian Impaired Driving Checkist.



© 2020 Allbiss Lawdata Ltd. All rights reserved. This is not a government web site.



For more information respecting this database or to report misuse contact: Allbiss Lawdata Ltd., 303-470 Hensall Circle, Mississauga, Ontario, Canada, L5A 3V4, 905-273-3322. The author and the participants make no representation or warranty  whatsoever as to the authenticity and reliability of the information contained herein.  WARNING: All information contained herein is provided  for the purpose of discussion and peer review only and should not be construed as formal legal advice. The authors disclaim any and all liability resulting from reliance upon such information. You are strongly encouraged to seek professional legal advice before relying upon any of the information contained herein. Legal advice should be sought directly from a properly retained lawyer or attorney. 

WARNING: Please do not attempt to use any text, image, or video that you see on this site in Court. These comments, images, and videos are NOT EVIDENCE. The Courts will need to hear evidence from a properly qualified expert. The author is not a scientist. The author is not an expert. These pages exist to promote discussion among defence lawyers.


Intoxilyzer®  is a registered trademark of CMI, Inc. The Intoxilyzer® 5000C is an "approved instrument" in Canada.
Breathalyzer® is a registered trademark of Draeger Safety, Inc., Breathalyzer Division. The owner of the trademark is Robert F. Borkenstein and Draeger Safety, Inc. has leased the exclusive rights of use from him. The Breathalyzer® 900 and Breathalyzer® 900A were "approved instruments" in Canada.
DrugTest® 5000 is also a registered trademark of Draeger Safety, Inc.. DrugTest® 5000 is "approved drug screening equipment" in Canada.
Alcotest® is a registered trademark of Draeger Safety, Inc. The Alcotest® 7410 GLC and 6810 are each an "approved screening device" in Canada.
Datamaster®  is a registered trademark of National Patent Analytical Systems, Inc.  The BAC Datamaster® C  is an "approved instrument" in Canada.