Roadside drug testing: Study casts doubt on device accuracy

Image: Mark Dadswell 

A new study has cast doubt on the accuracy of roadside drug testing devices used by police.

Sydney University’s Lambert Initiative for Cannabinoid Therapeutics found two devices commonly used by police in Australia may be less accurate than previously believed.

One of those devices, the Securetec DrugWipe, is used by Victoria Police.

The study found the device delivers false negative results 16 per cent of the time, and false positives on five per cent of tests.

Iain McGregor, senior author of the study, said the results are troubling.

“It’s a little bit of a concern given the increasing use of the tests and also the expense involved in purchasing them,” he told 3AW’s Neil Mitchell.

Mr McGregor said his study wasn’t the only one to find high inaccuracy results on roadside drug testing devices.

“We’re following on from studies that have been done in Europe over the years involving similar devices, which have basically shown that their accuracy is around 80 per cent.”

Press PLAY below for more from Iain McGregor.

Victoria Police Assistant Commissioner Stephen Leane said police testing has not found the inaccuracies detected by the study.

“We’re not finding the results that the study in Sydney found,” he said.

“We’re finding we’re in a complete different place.”

Mr Leane said results gathered from the devices are not used as evidence in court, so drivers who falsely test positive on the tests need not worry.

“This is a screening device, the same as a preliminary breath test,” he said.

“We don’t prosecute anybody based on a scan.”

When one of the devices indicates a positive drug result, police conduct a saliva test on the driver, which is sent off for forensic testing.

“Between three to five percent on the ones that we do come back as negative,” Mr Leane said.

“We’ll prosecute more than 95 per cent of cases that go through the Victorian Institute of Forensic Medicine for analysis.”

Press PLAY below for more.