For indispensable reporting on the coronavirus crisis, the election, and more, subscribe to the Mother Jones Daily newsletter.

David and Louise Turpin’s children were found in the filthy, stucco house, some shackled to beds, all 13 of them malnourished. They lived in “horrific” conditions, according to Riverside County prosecutors, and were beaten. Not until one of the children, a 17-year-old girl, escaped from the Perris, California, house and called 911 last month did anyone seem to know what was transpiring inside the house.

The abuse of the Turpin’s children, ranging from ages 2 to 29, allegedly went on for years, escalating over time. The Turpins have now been charged with multiple felony counts of child abuse, torture, and false imprisonment. (David Turpin has also been charged with one count of lewd act on a child.) Both have pleaded not guilty; last month, a Riverside County judge barred the couple from contacting their children in the next three years.

Hanging over the case as it begins to move through the legal system is the question of how the abuse was able to continue for so long. One reason, it seems, is because David Turpin essentially gamed the state’s education system by claiming that their residence was a private school—a status which, in the state, afforded the family near total autonomy and privacy. The Turpin case is of course an extreme one, but it reveals just how easily the homeschooling system in California—and in many places across the country—can be abused.

California law does not specifically authorize homeschooling, but rather families who want to homeschool their children must file an affidavit with the state’s Department of Education every year and register their home as a private school. In 2010, the year the Turpin family moved to California from Fort Worth, Texas, David Turpin did exactly that and established the City Day School. He continued to do so each year, eventually changing the school’s name to Sandcastle Day School. Those who register their homes as private schools are also required to get an annual fire inspection, but for an unknown reason, the regulation apparently wasn’t followed in the Turpin case; Perris city officials could not find records that an inspection had occurred at the house.

California requires private school employees receive a background check, parents who work with their kids are actually exempted from being checked to see if they have past criminal records or whether their households include someone who does.

And that—the yearly affidavit and fire inspection—was just about all that was required from Turpin to keep his children out of sight. And that’s far from atypical across the country. California does not necessitate periodic academic assessments; less than half of all states do. Parents in California are also not required to have a teaching license and they are never required to show students’ academic performance ProPublica found that in 2015, just 10 states required parents to have a high school degree to homeschool. In 25 states, homeschoolers are not required to get vaccinations, and in 11 states, they are mandated to get vaccinations but don’t have to submit records; in California, a law that requires vaccinations for all schoolchildren unless they have a medical exemption doesn’t include kids who are homeschooled. And although California requires private school employees receive a background check, parents who work with their kids are actually exempted from being checked to see if they have past criminal records or whether their households include someone who does. (Only two states, Arkansas and Pennsylvania, require such background checks on parents.)

While all this might seem incredibly lax, California actually requires more interaction between homeschools and the government than many states do. It at least requires families register the homeschool with the state; only 15 other states require that. Eleven states, including Texas, Oklahoma, and Michigan, don’t require any notice to the state whatsoever, let alone registration.

This environment, according to Christopher Lubienski, an education policy professor at Indiana University who has written about homeschooling, was a real factor in enabling the abuse of the Turpin children. The parents, he says, were certainly “able to use that practice [of homeschooling] as a shield from reasonable oversight from the community.” “I don’t think [this kind of abuse is] widespread, but it makes you wonder how many other cases are going on where abuses are going on,” Lubienski tells Mother Jones.

According to Rachel Coleman, co-founder of the Coalition for Responsible Home Education, a group of former homeschoolers who advocate for more regulation in sector, the Turpin case shouldn’t really be that surprising. She says she’s even seen other cases like this one. While no state tracks abuse involving homeschooling families, Coleman says that her organization has compiled data, while incomplete, of more than 380 cases of severe and fatal child neglect, such as physical and sexual abuse and food deprivation, involving home-schooling families since 2000; in those cases, they’ve found more than 120 children have died. While far from the norm, the Turpin case, Coleman argues, fits into a wider pattern of abuse behind the doors of homeschools. “The same laws that allow parents to create these thriving innovative settings allow parents like the Turpins to create private torture homes because there’s no accountability,” Coleman says. (Lubienski cautions that the figures, which come from news reports, aren’t particularly reliable and might even undercount instances of abuse, adding that the role of homeschooling in these cases could vary. “That said, it’s probable that homeschooling played a role—often by shielding abuse from authorities—in creating conditions in which abuse could happen,” Lubienski tells Mother Jones.)

The Turpin case and the lack of regulations that made it possible, Lubienski notes, is in part due to “the success of homeschooling advocacy organizations in rolling back or preventing reasonable regulations of the practice.”

Perhaps the strongest opposition force against legislating homeschools is Christian conservative legal advocacy group known as the Home School Legal Defense Association (HSLDA). Founded in 1983 by attorneys J. Michael Smith and Michael Farris, for decades the group has been providing legal representation to homeschooling families and mobilizing its thousands of members—now counting some 84,000—to rally against what they see as burdensome and controlling regulations.

For its part, HSLDA doesn’t believe the Turpin case says anything about the larger regulatory environment. In a letter to members on January 18, just days after the case first became public, HSLDA president J. Michael Smith cautioned that “hasty” legislation following the Turpin case “would be unfair to the thousands of law-abiding families in California who work hard to provide a safe and loving environment for their children.” Potential regulation, such as annual check-ins, he said, would be problematic because they treat “every homeschooling family as if they are suspected child abusers.”

The HSLDA said “hasty” legislation following the Turpin case “would be unfair to the thousands of law-abiding families in California who work hard to provide a safe and loving environment for their children.”

“Homeschooling parents around the country have demonstrated a high degree of success in raising and nurturing their children—giving them the tools to grow and flourish. And we believe that children thrive when their parents are able to tailor their education and upbringing to each child’s specific needs. This is the genius of homeschooling,” Smith added. “It would be inappropriate and unjust to regulate homeschool freedom because of this aberrant case.”

In recent years, lawmakers in at least five states have tried to pass measures to make homeschools more accountable. None so far have been successful, even in places with documented abuse. In 2015 in Michigan, which did not require parents to register their schools with the state, two children were found dead in a freezer in Detroit after, prosecutors said, their mother abused them and pulled them out of public school to homeschool them. The incident sparked a legislative effort that year to establish minimum reporting requirements, such as requiring kids to meet with a doctor, teacher, or other individuals twice a year and keeping records on which kids are homeschooled in the district. But the proposal failed to get even a hearing. Ellen Heinitz, the legislative director for Michigan Rep. Stephanie Chang, the lawmaker who introduced the measure and faced a barrage of angry phone calls from homeschooling parents, told ProPublica that year: “I’ve never seen a lobby more powerful and scary. They make the anti-vaxxers seem rational.” Meanwhile, in Iowa last year, after the death of a 16-year-old girl who was homeschooled and died of starvation, a bill to require quarterly checks on homeschooled students also failed to make it out of committee.

Also last year Kentucky state senator Ray Jones sought to pass a bill to prevent parents with a documented history of abuse or neglect from removing their children from public schools without court approval. Republican state senators refused to give the bill a hearing.

The past few years have actually seen a legislative push to give the homeschool sector even less oversight. In 2013, Iowa lawmakers ended requirements for homeschooling parents to report their students and curriculum to the local school district and allowed unlicensed independent instructors to teach children. And in 2014, Pennsylvania, which has some of the tightest restrictions on homeschooling, loosened regulations by ending requirements for submitting student portfolios and for parents to file standardized test scores to district superintendents. Similar moves took place in New Hampshire, Utah, Tennessee, and Arkansas between 2011 and 2015. And in March 2016, West Virginia Gov. Earl Ray Tomblin signed a bill that would, among other things, end annual requirements for homeschooling parents to report how well students perform and to notify local district officials of the decision to homeschool kids.

In the wake of the Turpin case, at least one California lawmaker is considering legislation that would force officials to conduct annual walkthroughs at homeschooling sites. “I am extremely concerned about the lack of oversight the State of California currently has in monitoring private and home schools,” state Assemblymember Jose Medina, who represents the district where the Turpin case took place, said in a statement recently. Assemblymember Susan Eggman, who represents Stockton, also suggested that the state should consider annual inspections. “If we’re not going to uphold educational standards, then for the love of God the least we can do is uphold health and safety standards,” Eggman told the New York Times last month. “We need to do everything we can for vulnerable minors before it becomes anything this tragic.” If they move forward with such plans, it’s almost certain they will face fierce opposition from the homeschooling community.

Just consider what’s happened over the past few weeks. On January 18, Iowa state Sen. Matt McCoy introduced a bill that require families to notify local school district superintendents of their intent to homeschool, prompting HSLDA to send a letter to members of the state Senate Education Committee to oppose the bill. On January 27, in New Hampshire, dozens of families showed up at a hearing to oppose a homeschool oversight bill to require state officials or school principals to review annual assessments for homeschooled students. The bill, introduced on January 11, is currently awaiting a vote in committee. Two days later, shortly after several Hawaii lawmakers introduced legislation to bolster homeschool regulations, HSLDA sent a “red alert” to its members in the state to “be proactive in voicing their concerns.” The bills would require parents to get approval from a public school principal when they intend to homeschool a child, make principals ask child protective services about whether there is a history of abuse at the child’s house, and add background checks for homeschooling families. The bills are still awaiting committee hearings.