I wonder about the marriage. Was it a close one? Were they friends, but living separate lives? Was there animosity? More than idle curiosity, just going through a process of elimination.
I see her lack of communication being she was out of cell phone range (easy if you’re traveling) As to her lack of comment to media etc now. She knows too much and it's best she keeps quiet. Let the FBI handle the case.
Did you both see the picture on the other thread, it appears that the yellow tape is still around the house.
IMO they are well aware of who is involved in his death & are just waiting till all the lab work, loose ends, etc are tied up for a conviction. They may also suspect a hit job and are tying the instigators into the perpetrators. In reality that takes time. We're not on a one hour TV show.
My gut feeling at the first was that when he came home he was attacked and left for dead. Possibly even tried to burn the body in the house across the street. Since he was able to recognize them, original perps hunted him down. His mission was to keep away/ get away from them.