It sounds like your fiance could be facing very serious charges. At this stage, it is certainly possible that a detective won't believe the story and it's the DA who then decides whether to bring charges based on the evidence.
Being innocent doesn't mean you don't need an attorney. Get someone on your side ASAP. The earlier an attorney gets started on this case, the better.
I'm sorry to hear your fiancé is facing such a serious and potentially life destroying allegation. Your fiancé needs a good criminal defense lawyer ASAP. I would recommend contacting some attorneys in your area to find one you are comfortable with and able to hire. If it is not financially feasible for you to hire an attorney of your choosing, the court will appoint an attorney to represent him. Feel free to contact me for more information. I handle cases in Hayward on a regular basis.
Perry Mason once said, "it's one thing to be innocent and another thing to prove it." Your fiancee is faced with a serious situation. He needs representation immediately. You will need someone who has experience with suggestability with child witnesses, along with some who has experince with pretrial motions regarding the reliability of the complaining witness. I can't provide enough info in this small space, but your fiancee needs someone with plenty of experience in this area.
Many respectable attorneys offer free consultation. I strongly suggest your fiancee contact at least one immedately.
The response above is not intended as legal advice since it’s impracticable to provide thorough, accurate advice based upon the query without additional details. It is highly recommended that one should seek advice from a criminal defense attorney licensed in your jurisdiction by setting up a confidential meeting. Moreover, this response does not constitute the creation of an attorney-client relationship since this message is not a confidential communication because it was posted on a public website, thereby publicly disclosing the information, which is another reason to setup a confidential meeting with an attorney.
These cases are extremely difficult and very serious. Any attorney with experience handling these case will be expensive, and don't try to find a bargain. You would likely be much better off with a public defender than a private attorney who does not like these cases or understand what he is doing. Beware of retainer agreements that only take you to preliminary hearing - you don't want to pay somebody thousands of dollars only to see them take the case to prelim and then dump you on the public defender - if this is all you can afford, just go with the public defender from the beginning.
The most helpful thing in a case like this is documenting the girl's history of lying and figuring out her motivation to lie in this case. You should make a list of people she has lied to - teachers, friends, other family members, etc. Provide this list of witnesses to the defense attorney immediately. It also helps if there is a known reason the girl is lying - is you ex involved in this perhaps? Is there something going on with your fiance and the girl - argument or some kind of tension? Anyway, you should think about this and try to figure out her motive for lying.
A case like this may not resolve quickly, and indeed can go to trial. You should prepare yourself for many court dates and a long, drawn out, and very emotional experience.
Ms. Wilkerson makes some very excellent points. The most important thing to remember is that these kind of cases are very difficult to defend because a jury can convict a person based on the child's testimony alone. The jury does not need any additional evidence such as DNA or medical evidence. I've handled nothing but sex cases for the last five years and my last 35 jury trials going back to December 2008 have been sex cases, including child molestation. These type of cases are also extremely expensive to defend and can easily run into six figures. It is critical that your boyfriend get an attorney that is knowledgeable, but given the expense and expertise involved, I would stick with the public defender. A reputable attorney simply can't afford to do these cases pro bono. As Ms. Wilkerson pointed out, beware of attorneys who give you a low ball figure just to take your boyfriend to preliminary hearing and then get out when the money is gone. Most importantly, you need to be proactive. Document all instances where your daughter has lied and look for a motivation behind her lies. Then get all this information to his attorney as soon as possible. Good luck to you and your boyfriend.