The process of prosecuting someone in the U.S. criminal justice system can seem onerous to the victims of sexual assault, and yet the experience can be cathartic. Much depends on one's expectations and preparation.
Below is an abbreviated description of how the system works, under ideal circumstances. Most sexual assaults are never prosecuted. The primary reason is because survivors do not feel they are able to file formal criminal complaints with the police. But, it could also be that the perpetrator is unknown or cannot be found, or the Commonwealth's Attorney feels that there is insufficient evidence to level criminal charges against him (or her). Often, acquaintance assaults fit the latter profile, but don't let this discourage you from giving it a try and meeting with the prosecutor to explore this option.
If prosecution does not occur, survivors do have other options that can be very effective and productive in the long run. More on those options here.
If you file a report, and if the Commwealth's Attorney feels there is a reasonable case, criminal charges are brought against the assailant. It is also to your advantage to have evidence collected at the emergency room. If you reported after the 72-hour "window" for effective evidence collection, you may still report, and still go forward with prosecution. If charges aren't filed, and you don't agree with that decision, you may ask the magistrate to issue a warrant. Ultimately, as stated above, the decision to prosecute is the Commonwealth's.
Once you have given a report to a police officer, the case is assigned to an investigator, usually a detective specially trained to handle sexual assault cases. In Charlottesville and Albemarle County, you will also be contacted by a Victim-Witness Cooridnator whose job it is to guide you through the legal system. You may also request a companion from SARA or the Sexual Assault Education Coordinator (if you are a UVa student) to accompany you on all interviews, etc.
If you decide to press charges, and if the Commonwealth's Attorney decides there is enough evidence, criminal charges are brought against the assailant. If the location of the assailant is known, an arrest takes place, and a bond hearing is held the next business day.
It may seem very impersonal, but from this point forward your role becomes solely that of "witness." It is the state of Virginia ("the People"), as represented by the Commonwealth's Attorney, which bring charges against the perpetrator, with your testimony serving as evidence. Your testimony is essential to successful prosecution, but you will only be in the courtroom during the time you testify. This means that you may be sitting outside the courtroom for hours until you are called. After you testify, the judge may allow you to remain in the courtroom.
Preliminary hearing, Grand Jury, and Circuit Court Trial