Usually if you are caught drink driving you will be charged under an alcohol specific offence. You will only be charged with driving under the influence (DUI) if for some reason police cannot properly administer breath or blood tests to check the level of alcohol in your system. The other circumstance in which you can be charged with DUI is if police allege that you were under the effects of a drug other than alcohol while driving.
Often police will base their decision to charge on an appearance, such as blood shot eyes, imbalance or slurred speech and sometimes this will be sufficient to prove the charge. Other times they will rely on the results of blood / fluid tests which show the presence of drugs. In order to prove that a person with drugs present in their system was actually under the influence of those drugs requires evidence from an expert. It is not uncommon for experts to disagree on this issue. For this reason it is important to make an early assessment of whether an independent expert report should be obtained. If the prosecution and defence experts disagree as to whether you were under the influence of a drug, there is a good chance you will be found not guilty.
Maximum penalty (1st offence): 9 months imprisonment / $2200 fine
Minimum disqualification: 3 months
Maximum penalty (2nd offence): 12 months imprisonment / $3300 fine
Minimum disqualification: 24 months