DRIVERS' BLOOD SAMPLES TO BE TESTED FOR CANNABIS

POLICE plan to analyse thousands of blood samples taken from drivers for
cannabis.

The approximately 4800 samples were taken to test for alcohol under the
Land Transport Act 1998, but "Police Minister George Hawkins said police
intended to analyse them for cannabinoids.

The tests were being done because "events worldwide" suggested the effect
of a combination of cannabis and alcohol on driving was "a far greater
problem than expected", Mr Hawkins said.

Unlike alcohol, there was no specific limit for cannabis above which a
driver was deemed to be legally incapable of proper control of a vehicle,
so police did not routinely analyse blood for the presence of cannabis.

Testing for cannabis in a driver's blood was usually restricted to
situations where a clearly. intoxicated driver involved in a bad driving
incident returned a negative test for alcohol, he said.

In the past five years, police had tested blood of about 20 drivers a year
for the presence of cannabis.

Mr Hawkins told The Dominion that no names or identification would be
attached to the blood samples, which would be used only to allow police to
get a general picture of the incidence of cannabis use among drivers.

They would not be used to pursue prosecutions for cannabis offences, he said.

"There is no comeback. We don't want police knocking on people's doors and
saying, 'Hey, we found -cannabis in your sample'.

"Police just want to get more accurate information on what percentage of
drivers had used marijuana."

That information could be very useful given the present debate about
decriminalisation of cannabis, Mr Hawkins said.

His "legal people" had gone over the proposal and were sure it complied
with the Land Transport Act.

He did not rule out wider testing of motorists for cannabis if a high
incidence of cannabis use was detected in the, samples, but he had no plans
to introduce it at present.

Mr Hawkins agreed traces of cannabis might remain in blood for long periods
of time, and its presence might not necessarily indicate that the driver's
abilities were impaired, "but then I'm not a chemist".

An Auckland University senior lecturer in criminal procedure, Scott
Optican, said the proposal raised "tricky" questions of law. In the Salmond
case in 1992, five justices of the Court of Appeal ruled that blood taken
from a driver for the purposes of testing for alcohol could also be used to
identify the driver by matching it with blood left on a car.

The Court of Appeal ruled that the blood could be used for other purposes
which came under the broad intention of the Land Transport Act, which was
to enhance road safety.

However, the proposal might breach the Bill of Rights, Mr Optican said.

It might interfere with people's right to legal advice and to give informed
consent, and drivers might claim they had been subject to unreasonable
search and seizure.

Drivers might have consented on legal advice, to giving blood on the
understanding that it was to be used for alcohol testing, but might not
have consented if they had known it would be used for other purposes, Mr
Optican said.

The act states samples may be taken for statistical purposes, but must have
the person's consent for that purpose, and samples taken for statistical
purposes are not admissible in court proceedings.