Law enforcement in Massachusetts may have a new tool that detects THC levels in saliva as well as identifies drugs such as cocaine, heroin and morphine. Although the device, developed by researchers at Stanford University, still needs to be tested and approved by regulators, scientists say it can successfully detect molecules of THC using a simple roadside spit test. The same method can be used to detect molecules belonging to other drugs as well.
Police face two obstacles in enforcing laws against the use of marijuana while driving. One is that some states do not have a maximum permitted limit for THC. The other is that there is not a quick test that can quickly check for the presence of THC in the same way that a Breathalyzer can measure blood alcohol. Usually, a blood or urine test must be sent to a lab so that it can be checked for THC, which presents a problem for police making a traffic stop.