Defences To Drink Driving

There are a number of defences to PCA and DUI charges. These can be divided into three main categories:

Establishing that the test was done unlawfully

Schedule 3 of the Road Transport Act sets out the circumstances in which police are lawfully able to administer a breath test, take blood or urine, or subject you to a sobriety assessment. A breath test or breath analysis must take place within two hours of you having driven. If you are able to prove that the test was conducted more than two hours after you drove then the results of the test may be inadmissible. This sometimes happens when police are delayed in attending an accident scene and do not breath test the drivers until more than two hours has elapsed. Another situation where this commonly arises is when police arrive to a car pulled over on the side of the road. Without supporting evidence from witnesses or CCTV it is very difficult to prove the person sitting in the driver seat actually drove the vehicle within the previous two hours.

Police are unable to administer a breath test or sobriety assessment if you are at your home – this is often referred to as the ‘home safe’ rule. This means the police cannot breath test you after you’ve pulled into your driveway or attend your home after an accident and ask you to submit to a test. If you live in a unit complex there are specific cases that consider whether or not the driveway or attached parking area are deemed to be part of your ‘premises’.

Establishing that you were not the driver

A police officer can require you to submit to a breath test if they ‘have reasonable cause to believe’ that you have been the driver of a vehicle or attempted to drive a vehicle. Although they only require a ‘reasonable belief’ to test you, they are required to prove ‘beyond a reasonable doubt’ that you were the driver if the matter is heard at court. Prosecutions are regularly lost and matters dismissed in cases where the police are unable to prove that the person charged was in fact the driver at the time.

Disputing the reading obtained

The Road Transport Act sets out presumptions in relation to the accuracy of instruments used to test a persons blood alcohol content (BAC). However accurate they are, these devices are testing your BAC up to two hours after you have actually driven. Depending on a number of factors your BAC may have risen from the time you were driving to the time that you were tested. People process alcohol at different rates and it may be possible to obtain an expert report from a pharmacologist showing that your reading at the time of driving would have been lower.

A person charged with low range PCA may be able to show that they would not have been over the limit at the time. Similarly, a person charged with high range PCA may be able to show that they would actually have been within the mid range PCA limits at the time of driving. We can then negotiate with the prosecution to have the charge changed to a lower range, resulting in a much shorter period of disqualification and lower fines as well.