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Breathalyzer machines used by police are error-prone, leading forensic scientist says

Consultant Nizar Shajani demonstrates the device B.C. police use to determine a driver’s blood-alcohol content.

Rafal Gerszak/The Globe and Mail

Breath-analysis machines used by police forces across B.C. are incapable of differentiating between mouth and blood alcohol, are prone to human error and should not be used to issue immediate roadside driving suspensions, according to a leading forensic scientist.

Those findings are outlined in an affidavit prepared by Nizar Shajani, a Burnaby-based forensic scientist who worked for the RCMP for 12 years and who has written numerous studies on blood-alcohol testing.

Vancouver defence lawyer Paul Doroshenko commissioned the affidavit, which was sent to the Office of the Superintendent of Motor Vehicles in June, 2012. Mr. Doroshenko has used the sworn statement in representing several individuals charged with roadside driving suspensions.

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"They're supposed to be screening devices," Mr. Shajani said about the machines in an interview with The Globe and Mail. "Screening devices when the police suspect there is alcohol in the body, but not used for evidentiary purposes in their current form."

The B.C. Immediate Roadside Prohibition program, first adopted in September, 2010, requires police officers to offer an individual suspected of intoxication two tests on two machines of the same model – Alco-Sensor IV DWF – with the lower result prevailing. Prior to June, 2012, only one test was required.

The machines register "Pass," "Warn," and "Fail," readings. A "Warn," is when blood-alcohol concentrations are between 50 and 80 milligrams per 100 millilitres of blood (0.05-0.08), resulting in an immediate three-day driving suspension. A "Fail" is anything above 0.08, an immediate 90-day suspension.

But drivers could have alcohol in their mouth from burping, for example, and register a reading above 0.08 even though their blood-alcohol is below the legal limit. The machines are not reliable at differentiating between the two, Mr. Shajani outlines in the affidavit.

Even with two tests, this remains a problem, he says. Drivers could blow a 0.15 on their first test and then 0.10 on their second – two failing tests. A sudden discrepancy like that would likely only occur with mouth alcohol, Mr. Shajani says, not with blood alcohol. But because there are no numerical values displayed on the devices, the officer might not be able to determine that the test was unreliable.

Mr. Shajani says the way to rule out mouth alcohol is for an officer to observe an individual for 15 minutes for burping or vomiting prior to the first test, and 15 minutes in between tests. He says that amount of time would likely get rid of any alcohol in drivers' mouths, if they don't burp or vomit.

A B.C. Ministry of Justice spokesperson said that a 15-minute observation period before and between tests is not a provincial policy, but officers "observe people closely and question them on the timing of their last drink."

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Mr. Shajani says the more advanced machines at police stations are able to differentiate between mouth and blood alcohol and should be used to determine someone's sobriety.

Mr. Shajani also raised concerns that the current model of breath-analysis machines doesn't record the device's calibration at the time the test is given, and says the device can lose its calibration at any time. While he says the current two-test scheme increases the chance of a reliable test, he said it is possible for someone to blow into two machines that are both out of calibration.

B.C. Minister of Justice Shirley Bond said in a statement that the OSMV requires devices to be checked every 28 days and police are required to submit sworn reports and documentation on the calibration of the devices for every suspension issued.

In January, police in Port Moody said that 14 of the roadside suspensions they issued in 2011 should be thrown out because an officer made an error when calibrating the devices. This recommendation followed one investigation by the Office of the Police Complaint Commissioner and another by the department itself.

Ms. Bond said the OSMV does have the authority to review suspensions if police pass on information that there was an error in calibration.

Mr. Doroshenko, the defence lawyer, says the problem with the program is that it punishes people on the spot.

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"Sometimes they find months down the road it's out of calibration or this device is malfunctioning but there doesn't seem to be any procedure in place to deal with that," he said. "But you've already paid your penalty and served your punishment."

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About the Author
News reporter

Daniel Bitonti is a Vancouver-based reporter with The Globe and Mail. Before joining the bureau, Daniel spent six months on the copy desk in the Globe’s Toronto newsroom after completing a journalism degree at Carleton University. More


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