I'll start with so many posts, apologies if this has already been covered. In regards to a person being charged, here are some basics that are followed everywhere. Police do not charge individuals (there is usually confusion created because the function of police and law enforcement is to investigate, write reports, take statements, collect evidence, etc. and then turn them over to the prosecutor. The prosecutor can be called a district attorney or as here in Illinois, a state's attorney. They are also commonly referred to as the "state".
In regards to charging a person the procedure is as follows:
There is a prosecutor assigned to review reports, statements, any other evidence turned into them. More often than not, that is more than enough to charge a person or to say no, I'm not going to charge a person unless I get more info (additional reports, evidence, etc.) There are times when someone comes in to ask for charges to be filed and that prosecutor faces the dilemma of telling someone there is not enough to file charges. There are also situations where a prosecutor may say to themselves, this is a weak case but I can't say no to the victim. There are several types of cases that could fall into this category and one is sexual assault cases. A more common one is a barroom fight. One guy loses the fight and is clearly injured but you have several witnesses at the bar that give conflicting accounts and most, if not all witnesses, including the victim, are intoxicated or at least have been drinking. In this scenario the prosecutor has to tell someone who is clearly injured that he sympathizes with them but there is just not enough to proceed. A lot of times if this happens and there are injuries you will see an individual sue someone in civil court since the burden is less and you can receive a monetary award. Hence the situation where someone is not charged or charged and not convicted but held liable in civil court.
Of course the easier route in situations as just described is to appease the person and file and see what shakes out in court. Yes, this happens.
As stated previously, there are two ways to proceed in regards to charging: grand jury or Preliminary Hearing. Grand jury's usually will convene for multiple days and the same jurors may serve for a month, coming in on numerous days. It's not for 30 consecutive days, prosecutors usually will wait until they have several matters to present. Of course, this is different from larger counties vs. smaller counties.
At a PH the state only needs to show probable cause exists to believe a felony was committed and it's in front of a judge (in Illinois misdemeanor's do not have PH's and I won't go into how they are charged and proceed).
Most PH's usually only take 10 to 15 mins. So, why would a prosecutor choose a grand jury? As stated before and most importantly the accused is not involved. No cross-examination of witnesses or presentation of their evidence. This is not so in a PH, so in a grand jury setting a prosecutor has the advantage and can control the procedure (although I've never seen a ham sandwich indicted.) Also, as previously pointed out, the defense does have the right to cross-exam and present evidence which is why you might hear of a PH lasting far longer than 10 to 15 mins. Defense attorneys can also use PH's as a way to garner evidence they might not see immediately or be able to make an evaluation of strength of case and believability of witnesses. Maybe leading down the path of trying to negotiate a resolution or if they believe there are grounds to file motions to limit evidence or dismiss on some technicality.
What I don't believe has been stated is sometimes prosecutors can use the grand jury for (HOWEVER, VERY RARE) to flush out a case which they, for whatever, reason don't believe should be charged. Remember, the prosecutor controls the presentation of evidence to the grand jury in a closed door environment. Again, this is rare but it has been done.
Putting all of this together, the type of alleged offense, the delay in charging, the barroom setting, maybe review of video, if any, and social media exchanges, might be why this was delayed. In other words, and I know this prosecutor has had her issues or may have an ax to grind or seeking publicity, but she obviously was not confident enough (for whatever reason) not to seek charges immediately and wait until early December.
If this is true it is my hope the Student Conduct Panel may very well proceed the same way. ie. "we just don't have enough to suspend. We are going to wait until more evidence comes to light, whenever that might be.
Damn, I hope this doesn't confuse matters.