JUST 24 PER CENT of drug driving incidents detected in 2006 led to convictions, and the failure to successfully prosecute in large numbers of contested cases is bringing the integrity of the regime into question, it has been claimed.
Lawyers specialising in road traffic law believe few defendants who contest drug driving charges are being convicted due to shortcomings in the law and in the testing procedures for blood and urine samples.
Figures compiled by the Central Statistics Office show that of the 113 drug driving incidents detected by gardaí in 2006 - the last year for which there are reliable figures - only 27 led to convictions. The data does not show how many of those defendants pleaded guilty.
The Medical Bureau of Road Safety tests blood and urine samples for drugs when gardaí make a specific request or when a person suspected of being intoxicated shows no evidence of being over the alcohol limit.
Barrister Martin Dully suggested problems have arisen with a "very significant delay" of up to four months in receiving the results of samples from the medical bureau, which appears not to issue a certificate until it has received the result of a second test, which is carried out in a UK laboratory.
"The significance of that is that the bureau are under a statutory obligation to carry out a test and issue a certificate as soon 'as is practicable'," he said.
According to barrister Justin McQuade, the fact that tests are being carried out by a scientist at a UK laboratory means there is a breakdown in the evidential sequence, which causes another problem.
"There is input into the certificate by someone who is not amenable to the Irish courts, and there is a break in the chain of evidence," he said.
Some defendants have recently evaded conviction by arguing that, because the bureau is not entitled by law to test for levels of drugs in a sample, it is not possible to ascertain the extent to which a defendant's driving was impaired.
Earlier this month, a judge at Ballyshannon District Court, Co Donegal, criticised the failure to test for the concentration of cannabis in a driver arrested by gardaí.
Judge Kevin Kilrane said the evidence was "too thin" to convict on a charge that carried a penalty of a four-year driving ban.
A similar defence was successful in a separate case in Wicklow District Court last month. A Garda spokeswoman said the force was satisfied there are "no issues" with the drug driving regime, but the Department of Transport said it was currently reviewing drug driving legislation, adding that it would seek to "identify best practice internationally and ensure appropriate legislation."
