My guess right now is they are developing through interviews in the community a clear picture of the who, and can make an educated guess about the what.
I think this is like Jorelys Rivera. I think it was someone they all know, in the community, and didn't give a second thought to him being around their kids. When they started interviewing everyone, many thought he (Ryan Brunn) acted odd, said odd things, spent too much time staring at the playground, etc. I think it's someone they all know and Jenise trusted.
Sadly, I do not think she's alive.I would sooooooooo love to be wrong!
I also think its going to be someone from the park, or doesn't necessarily live in the park but a visitor often so wouldn't be thought of as being suspicious if they were seen around. I really hope she will be found soon and really is just hiding somewhere.