Advances in technology have made detection of alcohol in the body a faster and more efficient process. We recently reported on the upgraded breath-test machines being adopted by Washington State Patrol.  The new machines are smaller, feature a touch screen, and have advanced processing power to give faster results.  Now, researchers from Washington State University are working to develop a similar machine to detect marijuana.

Traditionally, when police suspect a driver to be under the influence of drugs or alcohol, they will have the person submit to a chemical test.  If the police suspect alcohol, they will usually conduct a breath test.  However, because the breath tests are used to detect alcohol in the blood, if the police suspect the driver to be under the influence of drugs, they will have the suspect submit to a blood test.  Evidence of the person's blood or breath test can be used to prosecute the driver for driving under the influence (DUI).  In Washington state, as in Colorado, prosecutors have to demonstrate a threshold level of THC in the blood in order to charge a person for DUI of marijuana.

WSU researchers are developing a portable tool, similar to a breathalyzer, which police officers could use to test THC in the field, rather than transporting the person to the police station for a blood test.  Herbert Hill, a professor of chemistry at the University said the technology already exists to detect drugs, as used by airport security and customs agents.  That technology can be repurposed as a DUI breathalyzer for THC.

The breath test will not likely be able to determine the precise level of THC in the body, but rather, indicate whether some active THC is present.  In Washington state, drivers can be charged with a DUI if they have 5 nanograms or more THC in their blood.  Washington D.C., Oregon, and Alaska have recently voted to join Washington and Colorado in legalizing pot.  As more states join in decriminalizing marijuana use, there will likely be a greater call for the technology which can detect levels of THC in a person's body without having to resort to blood testing.

According to Hill, the new THC breath test could be helpful in determining whether to make an initial arrest, and could reduce the number of false positives.  However, it may not yet be reliable enough to be used as evidence in court sufficient to support a conviction.  Hill says his lab plans to finish their prototype this year, with testing to begin next year.

Lawmakers and law enforcement seem to be supportive of the new developments.  Democratic Senator from Seattle, Adam Kline, said, “WSU is going to be at the forefront, it seems to me, of supplying this kind of science and the technology that's based on it to police all over the country.”  The Washington State patrol may also look forward to the technological advancements.  According to spokesman Bob Calkins, the agency would “welcome anything that will help us get impaired drivers off the road.” Though he said law enforcement would not implement any new technology until is is fully tested and developed.