Currently in Illinois you can be convicted of DUI for any illegal drugs in your system.  You can see an article here on how that may change or stay the same.  All to often police officers seek blood or urine from individuals who have used drugs days before being pulled over.  This will be reviewed when the Court takes a look at a Peoria case where a man was found guilty with meth in his system.  This could mean in the future that prosecutor’s would have to prove the drugs caused impairment.