My friend adopted four children she is a Dr. One of the children, a girl is the product of a crack addick. This girl is now 14 and has so many medical and emotional problelms. Very, very few people could love, support and parent this child. The time, money and effort are more then most of us can imagine. Because her mother used drugs the entire time she was pregnant, this young girl will probably never have a normal life. She is bi-polar and other health related issues and suffers from mood swings that would make most of us drink.
Some of these children can be evil, there is something just not right in their brains. Yes I believe this mom when she says he would burn the house down. Imagine, laying in bed at night, worring if your child that you love, support and try to help 24/7 might kill you or another family member?

That he might stab a smaller brother or sister in the night, or sufficate with a pillow, or set the room on fire, throw a baby down the steps or put in an oven.

What would you do if you gave birth to a child like this? Were can you go for help, and what if you have no insurance or the meds arent' working and every night you live in fear of being murdered by your own child?

Frankly if he was all she said, I would have sent him back as well.
Sometimes evil cannot be stopped or helped and one has to protect ones family and one self.