We went down the path of trying to create a per se law. We went three years into our state legislature to try and pass a five-nanogram of delta-9 THC per se law. We did not end up with that. Instead, we ended up with what is called a permissible inference. If somebody is arrested for a DUI case involving marijuana, they are given a blood test, and if that toxicology reveals that they have five nanograms of delta-9 THC per millilitre of blood, and if the case went to trial, in Colorado at least, even with our misdemeanour DUIs, they are jury eligible. The jury would be given an instruction that, at five nanograms or more, you can infer that this person is substantially incapable of safely driving a motor vehicle. That tracks with what would be our DUI statute.
What distinguishes a permissible inference from a per se law is that, if you hit that limit, that's a violation of a per se law. It's not even really proving impairment, whereas, with a permissible inference, the way the instruction works is that it's a nudge to the finder of fact to say yes, they're impaired. However, then the other parts of the instructions say that you can consider other evidence and the defence is allowed to offer up anything that suggests that the person wasn't impaired. It's not the functional equivalent of a per se law.
That was one thing we did.