I'm sorry to see so much Kiirsi-bashing on this thread.
I have been a friend of Kiirsi's since before she knew the Powells, and though I live a long way away I have visited Kiirsi and her family, and have never met a kinder or more welcoming family.
I am not LDS and do not follow any organised religion, but the LDS are noted for their wider-family attitudes. If an LDS member is in trouble, other members of the ward will help in any way they can. Josh is definitely in trouble, and he is still nominally LDS, so they will help. If he is eventually found guilty and jailed, they will visit him in jail and pray with him. If he doesn't accept their visits, they will pray for him anyway.
Kiirsi and any other LDS people who knew Josh and Susan will try not be judgemental towards his failings, as a man, husband or possible murderer, but will try to help and support, and let him seek forgiveness.
It cannot be easy to forgive someone you believe may have murdered your best friend, who shows no apparent remorse, no desire to find their missing wife either alive or dead, and who is now skipping town to avoid facing their responsibilities and the results of their actions, but that is what Kiirsi is trying to do. At the same time she is organising a nationwide search for any news about Susan's whereabouts, and let's not forget she is still a full-time mom to her own three children, so she doesn't have the opportunity to go searching the woods and fields all day.