When people talk about driving under the influence, they often are referring to alcohol. But it’s important to remember that this is not the only way that someone can be arrested on allegations of impaired driving. It also counts as impairment if they’re under the influence of substances like marijuana.
There are certainly some unscientific ways for police officers to determine impairment. For example, they may ask people to perform field sobriety tests, which are notoriously inaccurate. Officers may also make judgment calls about whether or not they smell marijuana or if the person’s eyes are bloodshot.
This information may indicate to the officer that the driver is under the influence, but it certainly doesn’t prove that that’s the case. With alcohol, the police will often then turn to breath tests to measure a person‘s blood alcohol concentration. But this is impossible for a driver who is high.
There is no marijuana breath test yet
As noted by Wired, there is currently “no scientific way to tell if you’re stoned behind the wheel.” There’s no breath test that can give real-time results, for instance.
Even if the police perform a drug test, marijuana can show up for weeks for chronic users. Someone who uses medical marijuana every single day, for example, may always test positive for cannabis. But that certainly doesn’t mean that they are actually high at the time.
If they used marijuana the day before, it’s not going to affect their driving at all. But they would still test positive in a drug test, meaning that it is not an effective way to decide if someone was actually impaired at the time that they were behind the wheel.
Issues like this make impaired driving cases very complex. Those who are facing charges or who have been arrested need to know as much as they can about their criminal defense options.