Police always know a lot more than they will ever tell the media.. They are also very savvy about looking at a crime seen or an accident and seeing things differently than the rest of us.
Remember these are people that mainly graduated from college have studied Psychology, criminology, and see lots of things the rest of us will never have to deal with.
Once they are detectives, they are considered some of the best of the group.
They also know how to use the media.. They sometimes can give out the least amount of information and the press will dig up other things.
The mom is actually married to another man. The media discovered this and found the guy.
The Police are doing their job. To keep it all legal they are in no way going to share those parts and lose the evidence or let someone know they are under investigation.