POLICE TO TEST SAMPLES 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, but
Police Minister George Hawkins said police intended to conduct
analysis for cannabinoids on the samples taken under the Land
Transport Act 1998.

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

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, Mr Hawkins said.

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.

Over the last five years police had tested blood of about 20 drivers a
year for the presence of cannabis, Mr Hawkins said.

He said 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,
Mr Hawkins said.

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

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

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

He said his "legal people" had gone over the proposal and were sure it
complied with the 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 had no
current plans to introduce it.

Mr Hawkins agreed that traces of cannabis might remain in blood for
quite long periods of time, and that its presence might not
necessarily indicate that the driver's abilities were impaired.

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 Appeal Court 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 Appeal Court ruled that the blood could be used for other purposes
which came under the broad intention of the act - 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, Mr Optican said.

The act allows samples to be taken for statistical purposes, with the
person's consent, but they are not admissible as evidence in a court
of law.