the fact that FBI said "ultimately it could be a family member" makes me think they know it is a family member of someone in particular. the use of "ultimately" and "family" leads me to think they were speaking directly to someone.
I guess I'm very skeptical of the J/J's dad focus at the moment. I noticed the discrepancy in the basement but wasn't suspicious of it then or now. Remember this information came third hand. Humans make mistakes when relaying info. A small part of the story was heard over the scanner- I am sure Westminster Pd has spoken with the subject at length. They seems very competent and dedicated to this case. I think that the tone here is implying that he is at worst, involved and at best, complacent in Jessica's disappearance. I don't agree at this time.