When a child is taken from the parents, does the case worker need to have paperwork?

My fiance's brother lost his kids today, but the case worker didn't have any paperwork. I myself was in foster care and the case worker not only had paperwork but also had an officer present. So I don't know if the case worker is required to have paperwork when they remove the children from the home. (For the record, my brother in law is not at all abusive. He has done everything he possibly could to keep his kids safe. He has no idea as to why they took his kids.)