is wondering how no one seems to have noticed the alleged horrors happening to the turpin children. We were in shock. We were astounded. I've been crying all these days. I haven't been able to sleep. Everyone is completely heartbroken, sad, that it's so close to home. It can happen in a beautiful neighborhood like this. None of us knew anything. Only people we ever saw were the parents and the baby. Those children were starving right next to us. Reporter: In the case of the an ngula brothers, Suzanne said it would have helped her children if someone had paid attention. Do you wish one of your neighbors had shocked on the door or gone down the stairs to the security officer and said, you know, I don't know, there's something a little funny going on at that apartment on the 16th floor? If someone has a sense that there's something a little off they cannot just go once and see what's happening. They have to do that repeatedly again and again and again. And if they're still unsuccessful then they go to other authorities. Reporter: In fact, the angulos and turpin kids have something else in common. They were all home schooled. How many times did somebody from the state or board of education come and check on your home schooling to see that you were in fact home schooling and that these kids weren't being abused? There was one time when someone from the board of education came. So one time, that year? One time in all the 18 years that I home schooled. One time in 18 years? Yes. Reporter: The Angulo children were learning. The Riverside county district attorney Mike hestrin says that does not seem to be the case for the turpin children. These kids were supposed to be being home schooled, but as far as we can tell, they didn't have much education. Their reading and writing abilities are very rudimentary. Reporter: There are those who believe that in some cases, the decision to home school isn't about education at all but something much darker. Rebecca was home schooled beginning at age seven. They have specific ways that they talk about school to their children. They call school buses prison buses and call schools institutions. They'll say it's an institution like a prison. They say that we're much happier being home schooled and that we have much more freedom. Reporter: But Rebecca says that freedom for some children comes at a price. Having your children at home can become overwhelming. Because of that, home sl families end up putting a huge amount of emphasis on obedience. Reporter: Rachel Coleman is an advocate for responsible home schooling. She says for the estimated 2 million children home schooled in the U.S., it can be as good or as bad as the parents who use it. In the hands of well meaning parents, it can be a wonderful thing with innovative child-centered educational programs, but in the hands of parents that aren't well meaning and the parents of parents who are neglectful, things can get bad. Reporter: But Rebecca says that freedom, for some children, comes at a price. Where the turpins lived in California, all they were required to do was file paperwork, calling sand castle a private school, which they did. Dr. Barbara Knox studies child abuse and torture. She says the issue is not home schooling itself but the dangers that arise when it's misused to camouflage abuse. The question here is really how do we as a society protect vulnerable children when home schooling is being used to mask the extreme physical and psychological abuse that is occurring.