If anyone can answer and let me know the process from here and possible charges and outcomes I would appreciate it.
You want this. That is the law regarding possessing controlled substances in Illinois. This is the relevant part to you:
720 ILCS 570/402)(from Ch. 56 1/2, par. 1402)
Sec. 402. Except as otherwise authorized by this Act, it is unlawful for any person knowingly to possess a controlled or counterfeit substance or controlled substance analog. A violation of this Act with respect to each of the controlled substances listed herein constitutes a single and separate violation of this Act. For purposes of this Section, "controlled substance analog" or "analog" means a substance which is intended for human consumption, other than a controlled substance, that has a chemical structure substantially similar to that of a controlled substance in Schedule I or II, or that was specifically designed to produce an effect substantially similar to that of a controlled substance in Schedule I or II. Examples of chemical classes in which controlled substance analogs are found include, but are not limited to, the following: phenethylamines, N‑substituted piperidines, morphinans, ecgonines, quinazolinones, substituted indoles, and arylcycloalkylamines. For purposes of this Act, a controlled substance analog shall be treated in the same manner as the controlled substance to which it is substantially similar.
(a) Any person who violates this Section with respect to the following controlled or counterfeit substances and amounts, notwithstanding any of the provisions of subsections (c) and (d) to the contrary, is guilty of a Class 1 felony and shall, if sentenced to a term of imprisonment, be sentenced as provided in this subsection (a) and fined as provided in subsection (b):
Essentially, he is looking at a felony if he has:
(11) 200 grams or more of any substance containing any substance classified as a narcotic drug in Schedules I or II, or an analog thereof, which is not otherwise included in this subsection.
The penalty for this is up to 15 years in prison and a fine of $25000 or the street value of the drug, which ever is more. The mandatory minimum is 4 years in prison.
That is just for the oxycodone. The bath salts, it will depend at what exactly is in them. That covers such a wide range, it could be anywhere from 4 years to 30 years in prison.
Also could he be charged as an adult even though he's only 17?
In Illinois, 17 year olds with misdemeanors can be tried as an adult or child. Felonies at 17 are always tried as an adult in Illinois.
Listen to the lawyer. Do not let him talk to anyone about this except the lawyer. Expect him to go to prison for a minimum for 4 years, unless the defense attorney gets one hell of a deal.