CA was not at the Mall that night (but his wife and son believed he was). He also wasn't shy, but he was noticeably quiet throughout the press events, letting FA do all the talking. She tried to protect her son-in-law, but I'm not sure she truly knew what was going on(maybe that's why her husband was letting her talk...). DA might not have been directly involved, but her "associations" and behavior sure make her look guilty, and she may well have believed someone she knew was involved( whether it was Dad, Uncle, or ex-boyfriend).
CA's brother is a character of dubious reputation, who could've been involved.
RA has been very controlling of the investigation (if you can call it that) and "narrative", his entire adult life. Obviously, he's protecting someone or something. DA once said RA "has a deep-seated need for things to look the way he wants them to be" (or words to that effect).
The other player in this drama is ST. Why does she place herself at Minot at 12:30 pm, picking up her son, and interacting with the girls? The girls were between A/N store and the Mall, at that time. If they stopped back by the house (for any reason), on their way to the mall
1. It was back-tracking to do so
2. It's doubtful they needed coats (but possible, I guess)
2. They left the house alive, at that point, because we know they made it to the mall.