You, (or rather, your "friend") need to consult an experienced and capable criminal defense attorney immediately. The criminal consequences to a situation like this can be very severe. Do not expect to get advice from a public online forum. Anything you say might end up being used against you (or your "friend").
This is a serious charge and you should consult with a criminal defense attorney.
THESE COMMENTS ARE NOT LEGAL ADVICE. They are provided for informational purposes only. Actual legal advice can only be provided after consultation by an attorney licensed in your jurisdiction. Answering this question does not create an attorney-client relationship or otherwise require further consultation.