Legal Question in Criminal Law in United States

That depends on many factors. They include, among others, the minor's age, the details of the alleged assault, and the strength of the prosecutor's evidence. Prosecutors seldom aim for probation in cases of aggravated sexual assault, but they will sometimes make a deal with defense counsel.

The minor needs a lawyer ASAP if he doesn't have one already. If his family can't afford one, the court will appoint one at public expense. The young man's entire future may be shaped by what happens in this case, so he needs the best representation he can get.

You posted your question under "United States," without telling us which state the case is in. (You listed a zip code in Illinois, which may or may not be where the case is pending.) The relevant laws vary quite a bit from one state to another. In some states, minors can even be prosecuted and sentenced as adults for major crimes like this one. Please re-post your question under the correct state. That way more lawyers from that state will see it, and you are more likely to get useful answers.

Good luck.