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Impaired Driving FAQ

DUI & Impaired driving FAQ

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  • Brett McGarry has a track-record of successfully defending drinking and driving charges at trial in Ottawa.  These are commonly referred to as impaired, over 80, DUI, or DWI charges.

    Here are five tips to make sure you hire the best Ontario criminal lawyer for your drinking and driving case:

    Is defending over 80/impaired driving charges a significant part of the lawyer’s practice? Drinking and driving law is a complex and constantly evolving area of the law.  Constant research, education, and courtroom experience is required to stay up to date on the best available defences.

    Does the lawyer understand the technical aspects of breath testing machines? Cases are often won based on problems such as residual mouth alcohol, error codes, or a rising blood alcohol level defence.  Lawyers who lack technical knowledge will overlook such defences.

    Will the lawyer meet with you to discuss your case? Meeting with a lawyer allows you to evaluate their knowledge, competence, and professionalism.  After an initial meeting you should have a good idea of your potential defences.   The lawyer should be able to provide a range of the estimated costs.

    Avoid lawyers who make promises about the outcome of your case. It is unethical and impossible to guarantee the result of a case.  There is nothing wrong with being confident or optimistic about the outcome of a case.  An experienced lawyer, however, will give you a realistic assessment of your case and will tell you litigation always involves some uncertainty.

    Is the lawyer willing to go to trial to win your DUI case? The reality is that a successful result in a drinking and driving case usually requires a trial.  Your lawyer must have the courtroom skills to cross-examine police officers and experts in order to succeed.

  • Drinking and driving is a complex area of the law.  These cases are typically won in two ways:

    • Using motions to exclude evidence at trial because your rights were violated under the Canadian Charter of Rights and Freedoms.

    • Raising a reasonable doubt that you were impaired or over 80.

    Brett McGarry uses an exhaustive strategy to defend DUI impaired driving charges in Ottawa, including:

    • Excluding evidence, such as your Breathalyzer results,  because your rights were violated.

    • Cross-examination of the police officers to undermine the alleged observations of impairment.

    • Exploring the legality of the traffic stop.

    • Examining whether there were legal grounds for the police to demand breath samples.

    • Examining the breath testing procedures at the roadside and at the station for errors.

    • Considering whether the prosecution can prove that you were “driving” or had “care and control” of a vehicle.

    • Using the expert testimony of a toxicologist to show that your blood alcohol content was not over 80 mg of alcohol per 100 ml of blood at the time of driving / care and control.

    • Pursuing disclosure from the police and the Crown of all the evidence in your case.

    • Exhaustive legal research to ensure the judge has the best current case law to support your defences.

  • If you are convicted of a drinking and driving offence by an Ontario court, you will likely face the following penalties:

    1. A criminal conviction and a permanent criminal record.

    2. Driver’s license suspension for 1 full year. (Subject to reductions from the interlock program.)

    3. A minimum fine of $1,000 for a first offence.

    4. Potential jail time.

    5.  Insurance premiums will sky-rocket. The driver’s policy will be surcharged 100% for a minimum of two years.  Some people will be required to get insurance from an insurer of last resort in the area of $10,000 per year for several years.

    6. Installation of an ignition interlock device. The ignition interlock device will be in your car for 1 year at your expense.  It costs approximately $1,300 per year.

    7. Required to take a license reinstatement program. (The Ministry of Transportation’s “Back on Track” program must be completed before license reinstatement.)

    8. Travel restrictions. You may be denied entry into the US and other countries.

    These penalties are further explained below.

    Permanent Criminal Record

    The waiting time before someone is eligible for a pardon has increased to 5 years under the Conservative’s recently passed omnibus crime bill, Bill C-10.  Pardons have now been renamed “record suspensions” by Bill C-10.

    Canadian pardons are not recognized by:

    American border authorities.

    • Some provincial legislation, including the rules for calculating driving suspensions for subsequent driving offences under Ontario’s Highway Traffic Act.

    Criminal Code driving prohibition rules for subsequent offences.

    Criminal Code sections providing for mandatory minimum jail sentences for repeat drinking and driving offenders.

    A criminal conviction may preclude certain careers like becoming a teacher, a police officer, or a government employee, or make it more difficult. There may be consequences or reporting requirements for many professionals, including under the following legislation:

    • Regulated Health Professions Act

    • Registered Insurance Brokers Act

    • Real Estate and Business Brokers Act

    • Professional Engineers Act

    • Chiropractic Act

    • Veterinarians Act

    •Surveyors Act

    • Architects Act

    • Funeral Directors and Establishments Act

    • Social Work and Social Service Work Act

    • Private Security and Investigative Services Act

    • Early Childhood Educators Act

    Mandatory Driving Prohibitions & Potential Jail Time

    If you are convicted you will be subject to a mandatory driving prohibition under the Criminal Code. After a conviction your driver’s license will also be suspended under Ontario’s Highway Traffic Act.

    The Criminal Code says that the length of the mandatory driving prohibition for impaired driving or Over 80 are:

    • For a first offence, 1 to 3 years (subject to reductions from the interlock program).  A jail sentence of 18 months is the maximum penalty if the charge proceeds summarily.

    • For a second offence, 2 to 5 years, in addition to any period of jail.  The minimum jail term is 90 days.

    • For a third offence, 3 years or more, in addition to any period of jail.  The minimum jail term is 120 days.  The Ministry of Transportation will impose a lifetime driving ban.

  • High Insurance Premiums

    A driver’s insurance premiums will increase drastically after a conviction for impaired driving, Over 80, or refusing/failing to provide a sample in Ontario:

    • A driver who was paying $1,500 annually for vehicle insurance can expect their annual premium to increase to approximately $5,800 following a conviction.

    • The Ministry of Transportation estimates that after a conviction a driver’s insurance will increase by a minimum of $4,500 annually for three years, for a total increase of $13,500.

    A driver’s automobile insurance is affected in three main ways after a conviction for impaired driving or “Over 80”:

    • The driving record drops to the lowest possible point total of 0.  (The best possible driving record is a rating of 6.)

    • The driver’s policy will be surcharged 100% for a minimum of two years.

    • Some insurance companies will not insure people with alcohol-related driving convictions.  Drivers may be limited to companies who specialize in insuring high-risk drivers at increased rates.  High-risk drivers who are unable to find automobile insurance in the regular market may obtain insurance from the Facility Association.

    Additional Costs for Drinking and Driving Convictions

    In addition to thousands of dollars in increased insurance rates, you will have to pay:

    • A minimum fine under the Criminal Code of $1,000.

    • A Victim Fine Surcharge of at least $50.

    • A license reinstatement fee of approximately $150.

    • An installation fee for the ignition interlock device of approximately $150.

    • A monthly interlock device monitoring fee for a minimum of 9 months at approximately $105 per month.

    • A removal fee for the Interlock device of approximately $50.

    • The cost of the Ontario government’s Back-on-Track program of approximately $578.

    • The potential loss of employment income.

    The high financial cost of a conviction will last for many years.   It is worth contacting a criminal defence lawyer who focuses on impaired driving to fight your charges.

  • An interlock ignition device is installed into a vehicle to check the driver’s breath for alcohol before the vehicle can be started, and periodically while driving.

    Some people may be able to get back on the road sooner following a conviction with an interlock device.  In Ontario, the Reduced Suspension with Ignition Interlock Conduct Review Program now allows eligible drivers convicted for the first-time to reduce their licence suspension in return for installing an approved ignition interlock device in their vehicle and completing the remedial measures program.

    Everyone who drives your car will have to use the interlock device (including your family, employees or coworkers).  You will have to attend the Interlock dealer every two months to have the data downloaded from the machine.

    Drivers participating in the interlock program will be in one of two streams:

    Stream “A”: Drivers will have their licence suspension period reduced to a minimum of 3 months, followed by a minimum 9-month ignition interlock period.  To enter Stream “A” a driver must plead guilty within 90 days of being charged, enter into a lease agreement for an interlock device, and complete the assessment portion of the conduct review program.

    Stream “B”: Drivers will have a minimum licence suspension of 6 months and a minimum interlock period of 12 months. Drivers are eligible for Stream “B” even if they are convicted at a trial.

    • Drivers who do not to participate in the interlock program will be subject to the standard sanctions under the Highway Traffic Act: a 1 year license suspension, followed by 1 year period with an interlock device.

    Do not feel pressured into an early guilty plea because of the interlock program

    Do not feel pressured to plead guilty at the earliest opportunity, even if you do want to enter into Stream “A”.  It is in your interest to have a knowledgeable impaired driving lawyer review the disclosure because:

    • You may have viable defences.  There may be fatal problems with the Crown’s case.

    • Do not feel rushed.  You have 90 days from the day you are charged to fulfill the requirements of Stream A.  By retaining a lawyer immediately after you are charged, you will have plenty of time to enter into Stream A, after being fully informed of your options and defences.

    • Some offences are not eligible for the interlock program.  Drivers who are impaired by drugs are not eligible.  Offences where bodily harm is involved are not eligible.  Drivers with previous convictions may not be eligible.  In some cases your lawyer may still be able to negotiate your entry into the interlock program.

  • No.  Most people charged with drinking and driving offences believe that it is very unlikely that they can win their case.  This is often not the case.  There are several good reasons you should retain a lawyer before deciding whether to plead guilty:

    1. You are pleading guilty blind if you do not have a knowledgeable criminal defence lawyer review the strength of the prosecution’s case.  The prosecution often has serious problems with its case, which will not be obvious to an accused person.  For example, the prosecution will not tell you if:

    • Your Charter rights were violated and the evidence against you may be excluded at your trial.

    • Your breath testing was not done properly by the police.

    • The police did not serve you with the required documents.

    • The breath testing machine was improperly calibrated or maintained.

    • The police cannot locate key witnesses or evidence has been lost.

    • Evidence of the actual amount of alcohol you drank may rebut the machine’s breath readings.

    2. It is frequently less expensive to fight an impaired driving or Over 80 charge than to plead guilty, due to the high insurance premiums and fines which accompany a conviction.

    3. Hiring an impaired driving lawyer to analyze your case allows you to make an informed choice about whether you want a trial or not.

    4. Your lawyer may be able to negotiate reduced penalties even if you decide to plead guilty.

    Duty counsel at the courthouse does not have the time, or in some cases the expertise, to properly analyze your case.  Contact an impaired driving lawyer to analyze your case before pleading guilty.

  • “Over 80” means the amount of alcohol in your blood was over 80 milligrams of alcohol in 100 milliliters of blood.  Driving with a blood alcohol level over 80 is a serious criminal offence under section 253(1)(b) of the Criminal Code of Canada.

    For the offence of “Over 80” the prosecution does not need to prove that your ability to drive was impaired in any way.  The prosecution only has to show that your blood alcohol level exceeded 80 mg of alcohol in 100 ml of blood when you were (i) driving or (ii) had “care and control” of a vehicle.

    A driver may seem sober, but the “Over 80” offence will still be proved by the Breathalyzer readings taken at the police station.   Someone’s blood alcohol level can also be proved using blood samples in unusual circumstances, for example where injuries sustained in a car accident make taking breath samples impractical.

  • Being “impaired” by alcohol means that your ability to operate a vehicle is even “slightly impaired.”  The prosecution does not have to show that you were “markedly impaired” or “intoxicated” to get a conviction.  Being “impaired” can range from a slight impairment of your judgment or reaction time, to obvious signs of intoxication.  Impaired driving is a serious criminal offence under section 253(1)(a) of the Criminal Code of Canada.

    Proving Impairment

    Breathalyzer readings can be used to prove impairment.  Some toxicologists will testify that everyone’s ability to drive is slightly impaired at a blood alcohol level of 50 mg of alcohol in 100 ml of blood or higher.

    Observations by the police or civilian witnesses can be used to prove impairment. The common signs of impairment used at trials include:

    Admissions of Guilt: An accused may admit that they were impaired or say things like “I should not have been driving.”  Admissions to police, however, may not be admissible at trial if they were taken in violation of your right to silence or right to counsel.

    Nature of Driving: Abnormal driving may be in the range of a sober, but bad driver.   Bad driving may also be explained by a driver’s nervousness in the presence of police or caused by driving in an unfamiliar area.  Nevertheless, the following can be indicia of impairment:

    • speeding

    • driving significantly below the speed limit

    • weaving or erratic driving

    • poor parking

    • traffic infractions

    • failing to promptly respond to flashing police lights or a siren

    Accident: Accidents may be attributable to impairment, although some car accidents may be unavoidable.  Other accidents may have explanations such bad weather, road conditions, or a driver talking on a cell-phone.

    Physical Symptoms: Judges attach little significance to isolated physical symptoms of impairment given the lack of their scientific relationship to impairment, the police officer’s unfamiliarity with the accused’s usual demeanour, and alternative explanations for the symptoms.  However, a combination of the following physical indicia can lead to a finding of impairment:

    • bloodshot or watery eyes

    • flushed or red face

    • odour of alcohol

    • unsteadiness on feet

    • slurred speech

    • belching

    • heavy eyelids or falling asleep

    • aggressive or rude behaviour

    • unusual behaviour such crying or talking excessively

    Video Footage: Most police services now videotape the breath testing room and the cell-block.  These videos may show unsteadiness on the part of the accused.  On the other hand, these videos often contradict the observations of impairment by police officers by showing a sure-footed accused.

    Impairment of the ability to drive must be proven beyond a reasonable doubt to get a conviction.  These observations of impairment can often be effectively challenged at trial by cross-examination of the Crown witnesses, or by presenting alternative explanations for the signs.

  • It is a serious criminal offence to be in “care and control” of a car while you are impaired or over 80. You do not need to be actually driving a car to be convicted of a drinking and driving offence in Canada. The penalties for “care and control” are the same as for impaired driving.

    Being in “care and control” can be proved in two ways:

    1. Statutory Presumption: If you are found in the driver’s seat of a vehicle the Criminal Code says you are presumed to be in “care in control” of the vehicle.  Even someone sleeping in the driver’s seat is presumed to be in “care and control”.  This presumption can be rebutted by an accused.  It would likely be rebutted, for example, by an accused who was sleeping in the driver’s seat with the parking brake engaged and the engine off, who testifies he had no intention of driving.

    2. Using the Vehicle: Showing that you used the vehicle in such a way that it involved a risk of dangerously putting the vehicle in motion.  For example, someone who is trying to push a vehicle out of snowbank while over 80 or impaired is likely guilty of “care and control”.  By contrast, it will be much harder to prove “care and control” where an accused is sleeping in the backseat of a car.

    A determination of whether the accused was in “care and control” will be highly dependent on the facts of each case. There is an extensive body of case law on the subject.

  • Refusing to Provide a Sample

    A “refusal” charge is laid when a peace officer demands that you take a breath test (either at the roadside or at the police station) and you refuse to do so.

    Failure to Provide a Suitable Sample

    A “failure to provide” a suitable sample charge is laid when you deliberately frustrate the breath tests.  It is often alleged that the driver did not blow properly into the machine, for example, by “huffing and puffing” or obstructing the mouthpiece with their tongue.  The police will usually provide several chances to blow properly before laying a “failure to provide” charge.


    Refusals/failures to provide are serious criminal offences under section 254(5) of the Criminal Code of Canada.  The penalties for failing to provide an adequate sample or a refusal are the same as those for driving impaired or Over 80.  You can be convicted of both a refusal/failure to provide and impaired driving.

    Defences to “Refusal” and “Failure to Provide” Charges

    It is not a crime to refuse a breath sample if you have a “reasonable excuse”.  There is no all encompassing definition of a “reasonable excuse”.  A medical condition making it impossible to blow may be a reasonable excuse.    An injury making it dangerous to blow may be a reasonable excuse.

    It is not a crime to refuse a breath sample if the demand was not “valid”.  The Criminal Code provides strict requirements for roadside screening device and Breathalyzer demands.  If these requirements are not met by the police then the demand was not “valid”.

    Cases of “failing to provide” an adequate sample, as opposed to an outright refusal, allow for additional defences.  Here are a few examples of possible defences to “failing to provide”:

    • The instructions from the police officer on how to blow may have been unclear.
    • The breath-machine may have been improperly operated or maintained.
    • A distraught accused may be trying his or her best to provide an adequate sample, yet be unable to do so due to their emotional state.
    • The police did not provide the accused with enough chances to blow or a “last chance” to blow.

  • The most frequently violated rights of accused persons under the Canadian Charter of Rights and Freedoms in Impaired Driving cases are summarized below.  I would be pleased to discuss with you whether your Charter rights were breached.
    Here you could read the full text of the Impaired Driving Canadian Charter.

    Arbitrary Detention and Arrest (Section 9 of the Charter)

    It is a serious Charter violation if the police did not have sufficient grounds to arrest or detain a person.  Arbitrary arrests are serious because they result in people being handcuffed, transported to the police station in custody, detention in a jail cell while awaiting breath testing, automatic license suspensions, and the requirement to give breath samples.  Arbitrary arrests may occur where:

    • The police make an arrest based on an improperly administered roadside breath machine (e.g.,  where residual mouth alcohol is present due to recent consumption).

    • The police prematurely conclude that someone is impaired based on supposed physical indicia of impairment, without the assistance of a roadside breath testing machine.

    • A vehicle is stopped for a purpose unrelated to road safety.

    Unreasonable Search and Seizure (Section 8 of the Charter)

    Everyone has the right to be secure against unreasonable search or seizure. Absent a law to the contrary, individuals are free to do as they please. By contrast, the police may act only to the extent that they are empowered to do so by law.   The state can only force someone to submit to breath testing (i.e., a bodily search) if the police are acting in accordance with the law.   Illegal searches may happen where:

    • Roadside breath testing is done without a reasonable suspicion that the driver has alcohol in his or her body.

    • The police demand that a person provide Breathalyzer samples at the police station without reasonable and probable grounds for an arrest.

    • The police do not demand breath samples in a timely manner.

    • The police do not use the proper wording for demanding breath samples.

    Right to Counsel (Section 10(b) of the Charter)

    Everyone has the right on arrest or detention to retain and instruct counsel of choice without delay and to be informed of that right by the police.  The right to counsel is important because people who are arrested need immediate advice on how to regain their liberty and to avoid self-incrimination.  The right to counsel may be violated where:

    • The police fail to advise a detainee of his or her to counsel.

    • A person is not provided with access to his or her counsel of choice.

    • A person is not permitted to consult counsel before he or she is required to submit to breath testing.• The chance to speak with a lawyer is improperly delayed.

    Life, Liberty, and Security of the Person (Section 7 of the Charter)

    Section 7 of the Charter may be violated where:

    • The accused’s right to silence was breached.• Excessive physical force was used by the police.

    • A person who is under arrest is detained for an excessive period of time.

    • A person arrested for drinking and driving is strip searched without justification.

    Lost Evidence (Section 7 and 11(d) of the Charter)

    Everyone has the right to make full answer and defence to the charges against them, and to have a fair trial.  As a result, if important evidence is lost or destroyed then the charges may be dismissed.  This is one reason why it is important to pursue disclosure of all evidence.

    An Unreasonably Delayed Trial (Section 11(b) of the Charter)

    Everyone has the right to a trial within a reasonable amount of time.   If takes too long to get a case to get to trial the charge may be dismissed.  This may happen where court schedules are too busy, witnesses are unavailable, or there are lengthy delays in the Crown disclosing all the evidence.

  • The long-term costs of a drinking and driving conviction will outweigh the legal costs necessary to properly defend your case.  Your first priority should be hiring the right lawyer for your case.  The main questions people charged with drinking and driving offences have about cost are:

    1. How much will it cost to properly defend the case?

    2. How can I be certain about the legal costs?

    3. How can I afford a trial?

    1. How much will cost to properly defend the case?

    The cost of defending your case will depend on a number of factors:

    • The number of days of trial required. (Impaired driving trials usually last 1 to 2 days.)

    • The complexity and number of Charter motions needed to exclude evidence.

    • The amount of disclosure in your case (e.g., the number of witnesses, expert reports, etc.).

    • The amount of time the lawyer will devote to your case.

    • Whether hiring a private investigator, a toxicologist, or another expert is necessary.

    • Whether there are unexpected motions, such as a motion to dismiss that case for unreasonable delay, or a motion to obtain disclosure.

    After an initial meeting a lawyer should be able to give you a general idea as to cost.  After a full review of the Crown’s disclosure, a lawyer can then provide you with a comprehensive estimate of fees or a block fee quote.

    2. How can I be certain about the legal costs?

    Written retainer agreements are a good way to ensure that you know the services your lawyer will be providing for a given fee.  A retainer agreement may set out, for example:

    • The cost of the trial, as well as the costs of unexpected additional days of trial.

    • The nature of the Charter motions the lawyer will bring to exclude evidence.

    • The cost of hiring an expert witness or private investigator.

    A written retainer agreement allows you to plan ahead financially and may allow for a payment schedule.    Block-fees are often appropriate in drinking and driving cases, and can provide you with cost certainty.

    3. How can I afford a trial?

    No one plans to be criminally charged. Properly defending your charges will affect the rest of your life.  Here are some tips to make sure you can afford the best lawyer for your case:

    Do not assume you cannot afford a good lawyer. Talk with the lawyer to discuss a payment schedule.  Discuss ways to efficiently spend your resources.  Most good criminal lawyers will develop a financial plan with you because they want to ensure people have a strong defence.

    • Invest in your defence. Using your line of credit or credit card is a wise investment.   The cost of a criminal record and a lengthy driving prohibition will outweigh the cost of a good defence.

    Ask for help. Speak to family members and friends about your situation.

    There is time to raise money. An impaired driving trial usually happens 8 to 12 months after the date of the charge, giving clients time to raise funds.

  • If you have been charged with drinking and driving in Ontario there are a number of steps you can take to help win your case:

    • Make an appointment to discuss the case with a good impaired driving lawyer as soon as possible.

    • Write down everything you remember as soon as possible.  Document where you were, who you were with, what you ate, and exactly what you drank.  This includes documenting the type of drinks you consumed, its alcohol content, the size of glass you used, and the timing of each drink.  At the top of each page write “to my lawyer” to make sure your notes are protected by solicitor-client privilege.  Do not give your notes to anyone except your lawyer.

    • Preserve any receipts and credit card slips from bars or restaurants.

    • Exercise your right to silence.  Do not discuss the case with anyone except your lawyer.  If the police contact you, politely decline to make any statements unless your lawyer advises you otherwise.

    • Do not discuss the case or compare notes with potential witnesses.  Otherwise, it may be suggested that you tainted the witnesses’ memories.

  • It is impossible to say whether the Crown will proceed with an impaired driving prosecution without a careful review of all the evidence.   However, the reality is that that a trial will usually be necessary to avoid a criminal conviction due to government policy.  The Ontario Crown Policy Manual states that impaired driving charges can only be withdrawn in exceptional circumstances. You need a lawyer who is prepared to fight your impaired driving charge at trial.

    Effective negotiations with the prosecution can only happen after a lawyer knows all the weaknesses in the Crown’s case and has educated the client about his or her options.  In some cases, an informed client may want their criminal defence lawyer to enter into plea negotiations in order to:

    • Avoid minimum mandatory jail sentences for repeat offenders.

    • Avoid increased penalties where bodily harm or death has been caused by an accident.

    • Obtain reduced fines or driving prohibitions.

  • Yes. Even if a Breathalyzer test showed that you were over 80, there are ways to win your case.  Your case can still be won by showing that:

    • Your actual blood alcohol level was not over the limit.

    • The Breathalyzer tests were conducted in violation of your Charter rights.

    • The strict legal and technical requirements for Breathalyzer readings to be used at your trial are not met.

    The prosecution must prove you were over 80 at the time you were driving or in care and control.  A significant amount of time often passes between the time you are stopped and the testing at the police station.  Different people absorb and eliminate alcohol at different rates.  Without a further evidentiary link, the Breathalyzer results do not prove anything about your blood alcohol level at the earlier time of driving.

    There are two ways Breathalyzer results can be related back to show your blood alcohol level at the time of driving or care and control.

    (i) Breathalyzer Readings plus the Statutory Presumptions Back

    Section 258(1)(c) of the Criminal Code says that if certain requirements are met a judge must presume the blood alcohol level obtained from the breath tests at the station equals the level at the time of driving or care and control.

    The Crown must meet strict requirements to take advantage of the evidentiary short-cuts provided by the presumptions.  The most important requirements which must be proven are:

    • The first sample Breathalyzer must be taken within two hours of the alleged offence.

    • Each Breathalyzer sample was taken “as soon as practicable” after the time of the alleged offence. (The phrase “as soon as practicable” does not mean “as soon as possible”.)  If the police delayed the testing without a good reason, or the police cannot recall the reasons for the delay, then the presumptions do not apply.

    If any of the requirements in the Criminal Code are not met, then Crown cannot use the read-back presumptions.  This forces the Crown to call a toxicologist as an expert witness.  If the Crown does not call an expert, then they cannot prove you were over 80.

    (ii) Breathalyzer Readings plus Expert Testimony

    Using certain assumptions, a toxicologist can calculate backwards from the blood alcohol readings at the police station to determine your blood alcohol level at the time of driving or care and control.

    The Crown must prove all the assumptions and facts underlying the toxicologist’s opinion.  The toxicologist’s opinion can often be undermined by a defence lawyer in the following situations:

    1. Bolus Drinking / Last Drink Defence:

    The expert’s opinion will assume that a large amount of alcohol was not consumed rapidly in the time shortly before driving.  This is because the absorption of alcohol into the human body takes time.  As such, the accused’s blood alcohol level may be below the legal limit at the time of driving, if alcohol was consumed shortly before driving.  This is known as “bolus drinking” or the “last drink defence”.  The Crown must disprove “bolus drinking” for the expert’s opinion to be valid.

    The term “shortly before driving” usually means the alcohol was consumed in 15 – 30 minutes before driving.

    It can be difficult or impossible for the expert to calculate what constitutes a “large amount of alcohol” for a given person.

    2. When were you driving?

    If the Crown cannot prove when you were driving, then the times used in the expert’s report to calculate your blood alcohol do not prove anything.

    3. Post-driving consumption:

    If you drank alcohol after the time of driving it may undermine the expert’s blood-alcohol level calculations.

    4. Biological variability:

    People process alcohol differently.  The expert’s opinion may not apply to people who absorb alcohol abnormally slowly.  The expert’s opinion may not apply to people with an abnormally low blood-breath ratio, as the Breathalyzer assumes a ratio between the alcohol content in your blood and that in your breath of 2100:1.

    Defence Evidence & Restrictions on Evidence to the Contrary

    Until recently, an accused person could effectively challenge the statutory presumptions concerning the accuracy of breath readings with their own testimony.  The accused’s evidence concerning the amount he drank, coupled with a calculation by a toxicologist showing that the accused was not over 80, could raise a reasonable doubt that the Breathalyzer readings were accurate.  This is known as “evidence to the contrary”.  “Evidence to the contrary” is sometimes referred to as the “two-beer defence” or the “Carter defence”.

    A defendant’s ability to challenge the accuracy of the breath readings with evidence to the contrary has been severely restricted by the July 2, 2008 amendments to the Criminal Code in Bill C-2.

    Sections 258(1)(c) and (d.01) of the Criminal Code now say that the Breathalyzer results are “conclusive proof” of the accused’s blood alcohol level at the time of driving.  The breath tests can only be refuted by evidence that satifies all of the following conditions:

    • the Breathalyzer was malfunctioning or was operated improperly;

    • the malfunction or improper operation caused the machine to determine that the accused’s blood alcohol level was over 80 mg of alcohol/100 ml of blood; AND,

    • the accused’s actual blood alcohol level was below 80 mg at the time of driving or care and control.

    The amendments state that the accused’s evidence of alcohol consumption cannot be used to show that the machine was operating improperly.  In other words, even if the judge believes an accused that the amount of alcohol he consumed puts him below the legal limit, the judge must convict if the accused cannot show that the Breathalyzer malfunctioned.

    These amendments place an impossible burden on an accused person.  They raise a real possibility that innocent people will be convicted because they cannot show the machine malfunctioned.  The amendments have been subject to several constitutional challenges with varying degrees of success.

    Your criminal defence lawyer needs to be up-to-date on this rapidly evolving area of the law.  A decision from the Supreme Court of Canada on the constitutionality of Bill C-2’s restrictions on evidence to the contrary is expected in the spring or summer of 2012.

  • Drinking and driving trials usually occur between 8 to 12 months after the first court appearance in Ontario.  The waiting time will depend mostly on how long it takes to get all the Crown disclosure and the number of days the trial is expected to take.

    If your trial is unduly delayed, a motion to dismiss the charges under section 11(b) of the Charter can be made. For this reason, it is wise to move your case forward as quickly as possible.  It is also important for you to document the prejudicial effects of waiting for your trial, for example, on your employment or educational opportunities.

  • In Canada, a person accused of a crime cannot be forced to take the stand at his or her own trial.  The fact that you choose not to testify cannot be used against you in a trial.

    The prosecution must to prove its case beyond a reasonable doubt, based on admissible evidence. This is a very high burden.  As a result, a criminal defence lawyer can often create reasonable doubt without the need for the client to testify.

    There are cases when the best chance of winning requires a client to testify.  This decision should only be made after careful discussion with your lawyer.  If testifying is in your best interests, a significant amount of time should be spent by your lawyer preparing you to testify.

  • You will receive an automatic 90 day license suspension (ADLS) from the police when you are charged with over 80, impaired driving, or refusing/failing to provide a breath sample.

    You must not drive during this 90 day period.  If you drive, you will face new charges, high fines, possible jail time, a further license suspension of at least six months, and insurance consequences.

    You can get your license back from the Ontario Ministry of Transportation after the 90 day suspension, after you pay a reinstatement fee of $150. The reinstatement fee may be paid at any Driver and Vehicle Licence Issuing Office.

  • No. The 90-day suspension can only be appealed on the grounds of mistake as to identity of the driver or a medical reason for refusing a breath sample.
  • All drivers charged with having a blood alcohol concentration over 80 or who fail/refuse to comply with a demand to provide a breath sample will have their vehicle impounded for seven days.

    You will receive a notice from the police when you are released from the station saying where your car has been impounded.

    You will need to bring someone with you to drive your car, as you will be subject to the 90 day automatic driver’s license suspension.  You will also need to bring the documents the police gave you.


Nothing on in this FAQ should be taken to constitute “legal advice” or the creation of a “retainer”. The content of this document represents legal information only. For legal advice, please contact a lawyer with the specifics of your situation.

Drinking & Driving

Ottawa DUI Lawyer, Brett McGarry, regularly defends drinking and driving cases in Ontario. These are commonly referred to as impaired driving, over 80, refusing to provide a sample, DUI, or DWI charges. These are serious charges, which result in lengthy driving prohibitions, high fines, drastically increased car insurance, and even jail.

If you need more information on drinking and driving charges in Ontario, call or email Ottawa criminal lawyer Brett McGarry today. He would be pleased to help you understand your charges and defences.

Brett McGarry

Brett McGarry Criminal Law
200 Elgin Street, Suite 800 Ottawa, Ontario , Canada K2P 1L5
Phone: 613-884-8576 URL of Map