When Can Police Demand a Breathalyzer
Canadian Criminal Case Law Summary
As impaired driving lawyers, at Charitsis Law we examine every breath demand to see whether police followed the law. In R. v. Woods, the driver refused a roadside test and was arrested. More than an hour later, police tested him again at the station and obtained a “Fail” result.
Police used that result to demand a second breathalyzer test at the police station. The Supreme Court of Canada found that the station screening sample was not obtained under a “lawful demand”, and the Crown Attorney agreed the test was not taken voluntary.
Because police had no other grounds for the breathalyzer demand, the Court overturned his conviction for driving over .08, finding Woods not guilty.
If you’re facing an impaired driving charge, the timing of each breath demand matters. Call Nicholas Charitsis at 416-731-7113 for a case review of what police did and learn whether the breath test evidence can be challenged. Nicholas is a former Crown Attorney with 25 years of criminal law experience in Toronto and more than 350 five-star Google reviews.
If you’ve been arrested for a DUI charge, call and discuss your case directly with Nicholas Charitsis at 416-731-7113.
What Happened in R. v. Woods?
A roadside refusal turned into a “Fail” result at the police station. That result led to a conviction, but the story did not end there.
Police stopped John Woods in Winnipeg and noticed a strong smell of alcohol in his car. The police officer demanded a roadside breath sample. Woods refused, so police arrested him and took him to the police station, where he spoke with a lawyer.
What Happened at the Police Station
At the station, Woods indicated that he wanted to provide a sample. His first seven attempts did not produce a valid result. An officer then warned that he would be charged with refusing if his next attempt failed. Woods provided a sample, and the screening device showed “Fail.”
Police used that result to demand a further full breathalyzer test, to get a blood alcohol reading. When the breathalyzer test was taken, Woods blew over the legal limit, and was subsequently charged with driving over 80.
A the first court hearing Woods was convicted of driving over the legal alcohol limit. On appeal, the courts found that the station screening sample had not been obtained under a lawful demand or given voluntarily. The Supreme Court acquitted (found not guilty) Woods of the charge.
Relevant Case Law:
R. v. Woods — Supreme Court of Canada (2005 SCC 42)
[View the full decision on CanLII (Canadian Legal Information Institute)]
The Legal Issue Before the Court
The legal issue in Woods was, did the police have the authority to make the second demand for a breath test, considering that the driver refused when the initial demand was made?
What Is a Roadside Breath Test?
During the course of their duties a police officer may stop a driver and demand that they supply a sample of their breath into a Roadside Screening Device, called an approved screening device to check a driver’s breath for alcohol.
- This first test usually happens at the roadside. It gives a quick result, such as “Pass,” “Warn,” or “Fail.” It does not give the precise reading used to prove an over-80 charge in court.
- Where the driver fails the test, this gives the police officer reasonable and probable grounds to beleive that the drivers blood alcohol level is over the legal limit of .08 milligrams of alcohol per 100 millilitres of blood. e.g driving over 80.
Where the police officer has reasonable grounds and they arrest the driver, they police must then make a second breath test demand for a breathalyzer test at the police station.
What Is the Second Breath Test?
The second test is usually done at a police station on a larger machine called an approved breathalyzer instrument. A qualified breath technician operates it and normally takes two breath samples. Each sample produces an exact reading of the driver’s blood alcohol concentration.
These readings may be used as evidence in court.
Why Did This Matter in R. v. Woods?
Woods refused the first test at the roadside. Police later used the screening device at the station and got a “Fail.” They relied on that result to demand the second test.
The Supreme Court found that police had not obtained the station screening sample under a lawful demand. The Crown Attorney also conceded that Woods had not given it voluntarily. Since police had no other grounds for the second demand, the Court overturned the conviction and found him not guilty of the charges.
What the Court Confirmed
In Woods’ case, police made a new screening demand at the station. That demand was too late to qualify as an immediate roadside test. The Crown also conceded that Woods had not provided the station sample voluntarily.
The Supreme Court confirmed that
- a roadside screening demand must be made promptly, and
- the driver must respond immediately.
- A driver cannot refuse the test and then treat the same demand as still open more than an hour later.
As a result, police could not use the station “Fail” as their grounds for the second breathalyzer demand.
With no other grounds for that demand, the breathalyzer tests at the police station could not be used to support his conviction for driving over the legal alcohol limit.
Why R. v. Woods Matters
A breathalyzer result may look like the whole case. A lawyer looks at how police got that result.
Why the “Fail” Could Not Be Used
At first, Woods’ case looked straight forward. Police had a “Fail” from a screening device. They also had a later breathalyzer result showing he was over the legal alcohol limit. He was convicted of driving over 80 mgs.
But Woods had intially refused the original roadside test. Police arrested for refusing a roadside screening test, not for driving over 80mgs.
No Authority to Request a Second Breathalyzer Test
When they took Woods to the police station the police therefore had no authority to demand the roadside test a second time, more than an hour later. The law required a roadside screening test to be done forthwith. The first demand had ended when Woods refused, and the new demand came too late.
Could police use the station result because Woods agreed to give a sample? That was another possible question. But the Crown conceded that he had not given the sample voluntarily. Police had warned that he could be charged with refusing if he did not provide it.
That left police without a lawful “Fail” result to support a secondary demand for a breathalyzer test at the police station. Although the test was done, the court ruled that the evidence was not obtained legally and therefore the results of the tests could not be enter into evidence.
When the results of the breathalzyer test at the police station where excluded there was no evidence before the court to support a charge of driving over 80 mgs and the charge was dismissed (not guilty). cquittal.
How This Case Shapes Defence Strategy
The police are required by law to follow the law in demanding a breath sample, and where they don’t the charge may fail.
The Lawyers Review of the Case
R. v. Woods shows why a defence lawyer should trace an impaired driving investigation from the first police demand to the final breath test. The lawyer needs to know what happened at each step, not just what the machine recorded.
That review may include:
- When police stopped the driver and made the screening demand
- Whether the driver provided a sample, refused, or was unable to complete the test
- Whether police made another demand, and why
- What grounds police had for demanding the station breathalyzer test
- Whether a later sample was given voluntarily
In Woods’ case, the station “Fail” was the only ground police relied on for the breathalyzer demand. Once the Court found that the screening sample had not been lawfully obtained or given voluntarily, the later test could not support the conviction.
Every case has its own facts. A delay alone does not decide the outcome. The defence strategy is to examine the full sequence and identify any step the Crown Attorney may be unable to justify.
What This Case Means for You
A breathalyzer reading over the legal limit can make an impaired driving charge feel impossible to fight.
Woods was convicted at first. But when the courts looked at how police obtained the evidence, his conviction was overturned.
Why Speaking to a Lawyer Matters
You may not know which questions to ask about your own case. A lawyer can review the police notes, check each breath demand, and explain whether the Crown Attorney can rely on the test results. That review may uncover an issue that is easy to miss when you only see the final reading.
A Client’s Experience Speaking With Nicholas
“Nick went above and beyond during my consultation. He spent a significant amount of time reviewing my situation, explaining my options, and outlining possible strategies based on my circumstances. He was patient, knowledgeable, and genuinely cared about helping. Thank you again Nick and I wish you the very best!”
If your friends or family have urged you to speak with a lawyer, or the Crown Attorney has suggested you get legal advice, make that call. Nicholas Charitsis is a former Crown Attorney with 25 years of criminal law experience as a Toronto criminal lawyer.
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Frequently Asked Questions
Q. What is the difference between a roadside breath test and a police station breathalyzer test?
A. A roadside breath test uses a small device called an approved screening device. It helps police decide whether they need to investigate further. A breathalyzer test uses an approved instrument to measure a person’s blood alcohol concentration.
That test is usually done at a police station by a qualified technician. The two tests have different legal requirements.
Q. Do police need to suspect impaired driving before demanding a roadside breath test?
A. Not always. Under current Canadian law, police can demand an immediate roadside breath sample from a driver during a lawful stop if the officer has an approved screening device with them.
Police can also make a screening demand when they have reasonable grounds to suspect alcohol in a person’s body and the other legal requirements are met. The rules in R. v. Woods applied to an earlier version of the law.
Q. Does a “Fail” on a roadside breath test allow police to demand a breathalyzer test?
A. A lawful “Fail” result can help give police reasonable grounds to believe a driver committed an alcohol-related driving offence.
Those grounds may support a demand for breath samples using an approved instrument. Police must still follow the legal rules for making that further demand. A “Fail” result does not fix a problem with how the screening sample was obtained.
Q. Can police give a driver another roadside breath test after the driver first refuses?
A. The answer depends on the facts and the law that applies. In R. v. Woods, the driver refused a roadside demand and was arrested. More than an hour later, police obtained a screening result at the station.
The Supreme Court found that the original demand did not remain open indefinitely. The Crown also conceded that the later sample was not voluntary. That result could not be used to justify the next breathalyzer demand.
Q. Can a lawyer challenge a breathalyzer demand even if the driver failed a breath test?
A. Yes. A lawyer can review when each demand was made, why police made it, and whether each breath sample was lawfully obtained. In R. v. Woods, police relied on the later screening “Fail” as their only grounds for the breathalyzer demand.
Once the Court ruled that the screening result could not be used, the breathalyzer evidence could not support the conviction. The conviction was overturned, and the driver was acquitted.
