CG- I wrote in my earlier post that if the NCIS were called in to the guy's house, it is because there either is or was a case against him which falls under jurisdiction. It had to be relative to him because they would not as you wrote be involved in a civilian criminal matter on it's own. My guess would be the military angle here is why they are so tight lipped, it could be as simple as they are literally determining jurisdiction over the crime. If that is true, there is a different set of standards for the "usual and customary" needs of an investigation ie: probable cause and search warrants, interrogation, use of attorneys or jags, etc..
I honestly think they know the who, why and when of this case and are guarding it to protect a succesful prosecution. That being said, I have 2 issues, how was this young girl in a position to be molested by a family friend in the first place, and if a perp was indeed released, or she was about to testify and had reason to fear for her safety, she should have been under police protection. My heart aches for the pain she must have gone through and I pray for her soul's peace and that of her family.