How to Beat a DUI Charge: Top 100+ Common Defences

Disclaimer: Please note that the defences outlined on this page relate primarily to Driving Over the Legal Limit charges arising from breath tests. Blood sample cases, and other possible driving alcohol/drug related charges, including, Drug DUI, Refusal, and Fail to Comply with Demand, are beyond the scope of this article. For those charges, please visit the web pages specifically dedicated to those charges, or consult with our legal team of DUI Lawyers.

Structuring Your DUI Defences

If you are reading this article, you have likely been charged with a DUI under the following provision of the Criminal Code:

320.14 (1) Everyone commits an offence who

(a) operates a conveyance while the person’s ability to operate it is impaired to any degree by alcohol or a drug or by a combination of alcohol and a drug;

 –or–

 (b) subject to subsection (5), has, within two hours after ceasing to operate a conveyance, a blood alcohol concentration that is equal to or exceeds 80 mg of alcohol in 100 mL of blood;

Contrary to popular belief, there are literally hundreds of defences to DUI and Impaired Driving charges. Thousands of judgements of acquittal are published yearly. For the latest cases, visit www.canlii.org and type in: (“impaired driving” /p “not guilty”). Even whole books are written on the topic.

Although we can’t possibly cover all the ways to win a DUI, we will go over some of the most common ways, and review what you can do to get a head start on your defence.

Remember, you do not have to prove anything to win the case. The government (AKA, the police and prosecutor) has to prove that you are guilty beyond any reasonable doubt. If they mess anything up along the way from the time they start the investigation to the moment the judge makes a decision, you may be found not guilty.

Although, as mentioned, there are simply too many defences to count, most DUI defences can be grouped into several categories:

• Police fail to follow proper procedures, or to collect evidence properly, and as a result, you are not guilty;
• Police violate your Constitutional (Charter) rights during the investigation, and as a result, you are not guilty;
• Prosecutor fails to do things correctly at trial or leading up to trial, and as a result, you are not guilty; or
• You provide information either before or at trial to establish a defence, and as a result, you are not guilty

Many DUI defences fall into several of the above categories.

For example, if the police do not properly maintain the device they use to take your breath samples, this demonstrates:

1. a failure to follow proper procedures,
2. a failure to collect evidence properly, and
3. a violation of the Charter right to be free from unreasonable search and seizure.

Below is a list of many of the most common defences to DUI’s that we see in every day cases. For convenience, we have organized them in chronological order in the order they would typically arise during a DUI investigation, and have grouped them under 10 main headings.

1.  Unlawful Reason for Traffic Stop

If you were driving when the police pulled you over, the first question to ask is whether the stop itself was lawful.

In Canada, the police have the right to pull over any vehicle for the purpose of checking the following:

• Licencing;
• Insurance;
• Mechanical fitness; AND
• Sobriety of the driver

If you were pulled over for one of these articulated purposes, the stop will be deemed valid.  However, there are situations where the stop can be unlawful.

For example, suppose the police pull a vehicle over based on a hunch that the driver or occupants of the vehicle are involved in criminal activity. If there is no evidence to support this “hunch”, the stop itself can be deemed unlawful, and the evidence of impairment gathered through such a stop can be deemed inadmissible at trial.

Another example is in the context of racial profiling.  Where the police have no good reason to pull a vehicle over, and the most likely explanation seems to do with a person’s race or ethnic background, the traffic stop, along with the evidence of impairment gathered through such a stop can be excluded from evidence.

2.  Failure to Properly Identify the Driver or Time of Driving

Unless the police found you in the driver’s seat, they may have difficulty proving that you were actually the operator of the motor vehicle. This situation most often occurs when there is a collision, or when police receive a report of an impaired driver. If the police do not locate you in the vehicle when they arrive, they often cannot rely on your admission that you were the driver, and may be left with no way to prove who drove.

3.  Invalid Roadside Breath Demand and Breath Test

Just in this narrow portion of the investigation, police often fail to follow their training and approved procedures, and thereby fail to gather breath samples properly.

Part of the problem is that there are now two types of roadside screening demands:

• S. 320.28(2) Mandatory Alcohol Screening Demand; and
• S. 320.28(1) Reasonable Suspicion Alcohol Screening Demand

When employing the Mandatory Alcohol Screening Demand, the police are NOT required to have ANY indication that the driver was drinking.  There are still pending constitutional challenges to the lawfulness of this procedure, but there are also many conventional arguments available as well.

Most of the common defences to Mandatory Alcohol Screening and Reasonable Suspicion Alcohol Screening demands overlap, and can include the following:

• Driver is no longer in the vehicle when the breath demand is made
• Police improperly direct driver to exit the vehicle to do the breath test
• Police don’t have the Approved Screening Device (ASD) with them when the breath demand is made
• Police don’t make the breath demand in a timely fashion
• Police don’t articulate the breath demand properly
• Police don’t explain the breath demand
• Police don’t translate the breath demand (if driver has language problems)
• Police don’t administer the test in a timely fashion
• Police fail to ensure the ASD is calibrated properly
• Police officer conducting breath test not trained to operate ASD
• Police fail to ensure there is no mouth alcohol that may contaminate the breath sample
• Police fail to make sure there are no foreign substances in the mouth prior to the breath test
• Police conduct test when there already have “reasonable grounds” to arrest the driver

If the breath samples were taken improperly, they may be unreliable, and not capable of proving what they police or prosecutor expects.

Equally important is that taking of roadside breath samples is a “search and seizure”, and thereby triggers your “Charter” rights. This means that if the police failed to take samples from you properly, not only might the samples be unreliable, but taking of breath samples in such a way could also constitute a breach of your Charter rights. As such, the results of the breath test may be thrown out by the trial judge as a remedy for the breach.

4.  Invalid Evidentiary Breath Demand and Test

The Evidentiary Breath Demand and Breath Test refers to the breath testing procedure that occurs either at the police detachment or Checkstop bus/van. Unlike the pass/fail roadside breath test, this is the breath test that ultimately shows your exact blood alcohol level. The device that is used to take breath samples is called the “approved instrument”, and there must be two valid breath samples taken.

It is imperative that the police strictly adhere to their training and the approved process in demanding and administrating the evidentiary breath test. If they failed to do so, the results of the breath test can be deemed unreliable, or be excluded from the trial.  As with roadside breath testing, this process is replete with possible problems.

Invalid Evidentiary Breath Demand

The preconditions for a valid breath demand are specifically outlined in S. 320.28(1(a)(i) of the Criminal Code, which states as follows:

320.28 (1) If a peace officer has reasonable grounds to believe that a person has operated a conveyance while the person’s ability to operate it was impaired to any degree by alcohol or has committed an offence under paragraph 320.14(1)(b), the peace officer may, by demand made as soon as practicable,

(a) require the person to provide, as soon as practicable,

(i) the samples of breath that, in a qualified technician’s opinion, are necessary to enable a proper analysis to be made by means of an approved instrument

While the section outlining what is required for a breath demand is not very lengthy, there are many factors that can invalidate a demand, including:

• Insufficient reasonable grounds for the officer to believe the person was driving
• Insufficient reasonable grounds for the officer to believe the person’s ability to drive was impaired by alcohol
• Insufficient reasonable grounds for the officer to believe the person’s blood alcohol level is over the legal limit
• Failure of the officer to make the breath demand in a timely manner
• Failure of the officer to actually properly read the demand to the driver
• Failure of the officer to explain the breath demand if there is a lack of understanding
• Failure to translate the breath demand if the driver has language problems

Invalid Evidentiary Breath Test

Factors that can invalidate a breath test include:

• Police fail to ensure the approved instrument has been properly annually inspected
• Police fail to ensure the approved instrument is calibrated properly
• Police fail to ensure the alcohol solution used to test the approved instrument is also approved for use with the instrument
• Police fail to conduct the self diagnostic sequence prior to the test
• Police officer conducting breath test is not trained to operate the approved instrument
• Police officer’s designation as a qualified technician has expired
• Police fail to ensure there is no mouth alcohol that may contaminate the breath sample
• Police fail to ensure there are no other contaminants in the atmosphere when the breath samples are taken
• Police fail to make sure there are no foreign substances in the mouth prior to the breath test
• Police fail to ensure there are no blockages in the mouth piece used to take the breath samples
• Police fail to wait a minimum of 5 minutes between breath tests.
• Police wait too long between the two breath samples that must be taken
• Police take too many breath samples
• The results of the breath samples are too far apart (more than 20mg%)

5.  Invalid (or unlawful) Arrest for Impaired Driving or Driving over Legal Limit

In order for the arrest to be lawful, the police must have “reasonable grounds” to believe a criminal offence has been committed. In our case, the police must believe a DUI offence has been committed. This sounds simple, but there are a lot of components to what the prosecutor must actually prove to satisfy the court that the arrest was lawful.

Here are some of the critical parts:

• Police must believe the person being arrested was the driver or operator
• Police must believe the thing being driven or operated was actually a motor vehicle

If the arrest is for impaired driving, the police must also believe the following:

• That the driver’s ability to drive was/is impaired
• That the impairment was due to drugs and/or alcohol

If the arrest is for driving with a blood drug/alcohol level over the legal limit, police must also believe the following:

• That the drive has, within two hours after ceasing to operate the motor vehicle, a blood alcohol level over the legal limit

There are two further critical components of a lawful arrest.

First, the arresting officer must genuinely believe each one of the factors listed above that are necessary for a lawful arrest. If the officer did not turn his mind to one of those factors in your case, the arrest might be unlawful.

Second, the arresting officer’s genuinely held believe must be “objectively reasonable”. So even if the officer really believes you are impaired by alcohol, if there are no observations made to support that believe, the court may find that the pre-requisites for a lawful arrest have not been met.

Even if the police had the proper grounds for arrest, if they fail to properly inform the driver of the arrest, or what the arrest is for, this too can make an arrest invalid.

6.  Excessive/Unreasonable Force

If at any point during the investigation the police use excessive or unreasonable force on you, this can constitute a violation of your s. 7 Charter rights to “life, liberty, and security of the person”.

Some of the more common times and situations we see that lead to excessive/unreasonable force arguments include:

• Police unnecessarily ramming a driver’s vehicle to have it come to a stop;
• Police violently removing a driver from the vehicle;
• Police handcuffing a driver prior to arrest;
• Police slamming the driver on the ground or hood of the car in effecting an arrest; and
• Police violently shoving a detainee into a cell

Beyond use of cheer violence, we have successfully argued that our clients’ s. 7 Charter rights have been breached by other police action, such as degrading and demeaning conduct.

Examples of this include:

• Police failing to allow a driver to put on their shoes before being forced to exit their vehicle and walk through the snow
• Police failing to allow a driver (typically female) to cover up before being removed from the vehicle and arrested
• Police failing to allow a detainee to use the bathroom
• Police forcing a female detainee to remove too many layers of their clothing in holding, including their bra
• Police forcing male and female detainees to use a bathroom which has video cameras that record their use of the bathroom and/or have a live feed of it going to the police monitoring desk

In these types of cases, any evidence obtained during or in connection to the unreasonable or excessive force may be thrown out by the trial judge as a remedy for the breach of your rights. In exceptional cases, the judge may even “Stay” the proceedings, which is an even stronger remedy.

7.  Failure to Provide Right to Counsel

Your right to counsel is one of the most fundamental constitutional rights you have when dealing with the police.

To be exact, the right to counsel states as follows:

10. Everyone has the right on arrest or detention:

(a) …

(b) to retain and instruct counsel without delay and to be informed of that right;

For more information on your right to counsel, visit: https://www.justice.gc.ca/eng/csj-sjc/rfc-dlc/ccrf-ccdl/check/art10b.html

In virtually every police investigation, the right to counsel is triggered upon detention. In DUI cases, however, the right to counsel may be suspended until the roadside breath testing is concluded. In every case, where the right to counsel is triggered, there is both an “informational” and “implementational” component.  That is, there are specific things the police had to advise you about calling a lawyer, and specific things the police had to give you the opportunity to do to contact a lawyer.

Some of the more common ways the informational component of this right is violated is as follows:

• Failure to inform the detainee of their right to counsel without delay
• Failure to inform the detainee of their right to counsel at all
• Failure to inform the detainee of the right to counsel through an interpreter
• Failure to explain the right to counsel if the detainee does not understand
• Failure to inform the detainee that they are entitled to call a free legal aid lawyer
• Failure to inform the detainee of the free legal aid lawyer number
• Failure to inform the detainee that they can call any lawyer they chose from a phone book
• Failure to inform the detainee that they can call a lawyer they already know
• Failure to inform the detainee that a telephone will be provided
• Failure to inform the detainee that telephone books will be provided
• Failure to inform the detainee that they can contact directory assistance to find the number of a lawyer of their choice
• Failure to confirm the detainee understood their right to counsel
• Failure to ask if the detainee wants to call a free lawyer or any other lawyer
• Failure to make a note of the detainee’s response regarding calling a lawyer
• Failure to make clear that the right to counsel is ongoing
• Failure to clear up any ambiguous answers given by the detainee

Some of the more common ways the implementational component of this right is violated is as follows:

• Failure to allow a detainee to call a lawyer at the earliest reasonable opportunity
• Failure to allow a detainee to call a lawyer from the roadside if circumstances permit
• Failure to allow a detainee to use the detainee’s cell phone to call a lawyer if circumstances permit
• Failure to provide a working phone to the detainee to call a lawyer
• Failure to provide the detainee with the free legal aid lawyer number
• Failure to provide the detainee with phone books
• Failure to provide the detainee with directory assistance to find a number for the lawyer of the detainee’s choice
• Failure to provide the detainee with their cell phone to find contact information for the detainee’s lawyer
• Failure to assist the detainee with finding the number for the lawyer of the detainee’s choice
• Failure to allow the detainee to call a friend or family to assist with finding, reaching, or retaining a lawyer
• Failure to allow a detainee to call more than one lawyer
• Failure to allow the detainee to call long distance to contact a lawyer of their choice
• Failure to allow a detainee to leave a message for a lawyer to call back
• Failure to allow a detainee to wait a reasonable time for a call back from a lawyer
• Failure to verify that the detainee spoke to a lawyer
• Failure to verify that the detainee is satisfied with their opportunity to call a lawyer
• Failure to provide the detainee with privacy in calling a lawyer
• Interrupting a detainee’s phone calls to see if the detainee is done with the call
• Failure to allow detainee to look for their own lawyer
• Failure to allow detainee to make their own phone call to a lawyer
• Making disparaging remarks about a particular lawyer a detainee wants to call
• Dissuading the detainee from calling a lawyer
• Recommending a particular lawyer over another
• Streaming or channeling a detainee to legal aid over a private lawyer
• Failure to provide interpreter services to contact a lawyer (if language is an issue)
• Failure to confirm that the detainee is waiving their right to call a lawyer
• Failure to read a formal “waiver” of the right to contact a lawyer to the detainee if the detainee no longer wants to contact a lawyer

Despite the right to counsel being such a critical right, police fail to respect people’s Charter rights far too often. If any of the scenario’s on this list apply to you, it may constitute a defence to your DUI.

8.  Failure to Preserve and Provide All Relevant Evidence to Defence Counsel

Even if the police did everything right during the investigation, you may still win your DUI if you can establish that the police or prosecutor failed to preserve or provide you with all the evidence to which you are entitled. This is called your right to make full answer and defence, and the right to disclosure, which is part and parcel of your s. 7 Charter right.

If you think police gathered evidence that they failed to disclose to you or your lawyer, it is definitely an area worth investigating.

The most common types of evidence that the police and prosecutors fail to disclose include the following:

• Police notes
• Police Car Digital Video
• Body Worn Camera Video
• Disciplinary records of police officers
• Witness statements
• Criminal Records of witnesses
• 911 audio calls
• Maintenance Records for the Roadside Screening Device
• Maintenance Records for the Approved Instrument

Specifically relating to the Approved Instrument, there is not only a constitutional obligation to provide various maintenance records, but also a statutory one, inscribed directly into the Criminal Code under s. 320.34 (1) as follows:

320.34 (1) In proceedings in respect of an offence under section 320.14, the prosecutor shall disclose to the accused, with respect to any samples of breath that the accused provided under section 320.28, information sufficient to determine whether the conditions set out in paragraphs 320.31(1)(a) to (c) have been met, namely:

(a) the results of the system blank tests;
(b) the results of the system calibration checks;
(c) any error or exception messages produced by the approved instrument at the time the samples were taken;
(d) the results of the analysis of the accused’s breath samples; and
(e) a certificate of an analyst stating that the sample of an alcohol standard that is identified in the certificate is suitable for use with an approved instrument.

These records must be provided in each and ever DUI case where the prosecutor intends to rely on the result of breath samples taken on an approved instrument. Our legal team always carefully reviews these documents to determine if all the right information has been provided and will definitely be sure to do the same for you.

9.  Failure to Bring Case to Trial Within Reasonable Time

Even if police conduct their investigation properly, and disclose all the relevant information to the defence to establish your guilty, you can still win your DUI if the trial does not proceed within a reasonable time frame.

This is because one of your rights under the Charter of Rights and Freedoms is s. 11(b), which states as follows:

11. Any person charged with an offence has the right:

(a)…
(b) to be tried within a reasonable time;

What is a reasonable time? The Supreme Court of Canada set a limit of 18 months to bring a DUI case to conclusion in Provincial Court.

Some of the more common reasons for delay which you likely have no control over, but may put the overall timeframe over the limit, may include:

• Police delay in issuing the first court appearance
• Police or Prosecutor delay in providing the complete investigative file to defence counsel
• Prosecutor unavailability for trial
• Police or other witness unavailability for trial
• Court unavailability for trial

There may be a myriad of other reasons that unnecessarily delay the court process. Whatever the reason, if more than 18 months go by from the date of the offence to the date the case wraps up, our legal team can file a constitutional challenge to the case, citing unreasonable delay, contrary to s. 11(b) of the Charter.

10.  Failure to Present all the Necessary Evidence at Trial

If all else fails, there is an “anything can happen” factor that is always present when you go to trial.  Even if the deck seems stacked against you on paper, you never know how things will turn out at trial.

Remember, what ultimately matters is not how strong the case looks on paper, but rather what the police and prosecutor are able to prove in court. Having defended more than 10,000 DUI cases, our legal team has seen even the seemingly strongest of cases fall apart at trial.

Here are some of the common, and not so common, reasons things can fall apart last minute at trial:

• Prosecutor is double booked on more than one case on the same day, and the DUI is withdrawn or dismissed
• Court room has too many trials booked for the day, and the DUI is withdrawn or dismissed
• Court house close on trial date due to weather, or other emergency, and the DUI is withdrawn or dismissed
• No court rooms available, or Judge is not available, and the DUI is withdrawn or dismissed
• Prosecutor fails to subpoena police officer or an essential witness, and the DUI is withdrawn or dismissed
• Police or essential witness simply doesn’t come to court for trial, with no good reason, and the DUI is withdrawn or dismissed
• Police or essential witness attends court, but forgets critical documents or notes, and the DUI is withdrawn or dismissed
• Prosecutor fails to disclose essential documents to the defence, and the DUI is withdrawn or dismissed
• Prosecutor fails to ask the witness any questions about a key component of the case, and the DUI is withdrawn or dismissed
• Police or essential witness can’t recall a key component of the case, and the DUI is withdrawn or dismissed
• Police or essential witness recall key component of the case incorrectly, and the DUI is withdrawn or dismissed

Why You Should Defend Your DUI

With DUI cases, there is only one guarantee.

If you plead guilty, even on a first offence, you are GUARANTEED to lose and have the following consequences:

1. 1. Minimum $1000 Fine;
   2. Minimum 1 year Canada-Wide Driving Prohibition; and
   3. Automatic Criminal Record

If this is a second or subsequent offence, the consequences become significantly worse. These are mandatory minimum sentences legislated into the Criminal Code. As such, the judge that hears your case cannot give you any lesser sentence than these minimums, no matter how clean your prior record, how sympathetic your circumstances, or how much you have done since the incident to better yourself. From this standpoint, there is no downside to testing the case at trial. We know it’s a huge gamble to hope things go wrong a trial, but sometimes, that’s all you’ve got. And sometimes, that’s enough to win the DUI!

Another way to put it is this: if you can’t afford a DUI, you can’t afford not to go to trial. Call or email us for your free consultation.

We would be happy to go over:

• your documents,
• your version of events,
• the court process,
• the fee structure, and
• what we can do to help.

Let our legal team of DUI lawyers help you get your life back. It is possible to defend your DUI. Give us a chance to earn your business and prove that we re the right team for you.