I am a mother of an autistic son. As others have said, you can not begin to imagine the intricacies of raising a child with a developemental disability. From the time of birth until about 7, he would fly into a frustrated rage for something like a tag on his shirt bothering him, or because you didn't cook his food hot enough. You work through this stuff and eventually it may or may not get better. Every autistic child is different, and you never ever know what your day is going to be like, good, bad or more often than not... ugly. You just have to love your way through their rough spots.
I can't imagine what this family is going through. I can imagine they are already carrying enough guilt. Regardless of their religion, they deserve the utmost respect for choosing NOT to institutionalize a child that can be difficult to raise, and giving him a stable home. I applaud them, and wish I could personally hug his Mother very tightly right now. She didn't sit on him until he stopped breathing, the cops did. She must be going through hell right now.