Prior to the THC based DUI statute's amendment, any amount of THC could result in a conviction for DUI. There was no scientific threshhold that required a certain amount of THC within one's body prior to a presumption of intoxication arising. As compared to ethanol based DUI offenses, a person is presumed under the influence of alcohol if their body's alcohol concentration is at or over .08 as defined in 625 ILCS 5/11-501.2. Prior to the law change, any amount of THC would raise the presumption that the driver was under the influence of THC. Now the State must prove the subject's body THC content is at or greater than 5 nanograms of THC per milliliter of whole blood.
In the practice of law it is a good thing to know what legal standards apply to this offense. As a defense attorney I can raise this issue effectively before a jury and put forth my client's best option to win the case if the State is unable to prove what amount of THC is in the client's body. Currently when a bodily fluid is taken as evidence the substance is packaged and sent to the forensic laboratory for analysis. Most times the blood or urine test will return with simply a "THC Metabolite Detected" finding. This scientific conclusion does not establish the 5 nanograms of THC per milliliter presumption as there is no numeric finding. The mere fact that THC is detected does not raise the presumption stated in the DUI statute. As of the date of this posting it is my understanding that the Illinois State Police cannot perform testing to a nanogram measurement due to funding issues. Sample must be sent out to laboratories for subsequent analysis should the State seek to obtain such measurement.
Because of the above-stated problem the State will have to use a considerable amount of time to send the substance to a second lab should desire to obtain a scientific measurement of a bodily fluid in a DUI case. In Illinois all persons charged with DUI have the right to a jury trial within 160 days under the Speedy Trial Act. I recommend announcing ready in any case where your client has been charged with a THC based DUI and the State has only received the "THC Metabolite Detected" report from the ISP lab. By announcing ready you have cause your client's speedy trial clock to begin ticking. Of course, a written demand must be made to avail your client of this right. But assuming you have filed the necessary pleading, the clock begins the 160 day countdown.
I have success resolving DUI cases in this situation by announcing ready for trial. Some prosecutors don't understand that the simple THC Metabolite detection is legally insufficient to convict in a DUI case.