DES MOINES  First-grader Matthias Beattie this week joined the hundreds of U.S. children suspended each year under post-Columbine "zero tolerance" policies when he took a shotgun shell to his school. The difference is that Matthias is home-schooled. The 6-year-old Carlisle boy takes a class once a week through a Des Moines school district program that pairs public school teachers with home-schooled children. The boy's parents say his one-week suspension lacks common sense. "Matthias is a little kid from the farm, and he did not have intent to do any harm," his mother, Charlene Beattie, said. School officials also never made clear that the policy applies to home-schooled children, she said. Matthias isn't a public school student in the eyes of state law, and his class meets at a church. But district officials say Matthias and other home-schooled students are bound by discipline policies. "Even though you spend 95% of your week home schooling, you are enrolled in the public schools," Leslie Dahm, the district's home-schooling coordinator, said in an e-mail to Matthias' parents this week. Dahm called live ammunition a "serious threat" for which the school district could be sued. Leigh McGivern, a district spokeswoman, said Wednesday she wasn't familiar with the incident. But she said school policies are drawn up primarily to protect students. "Whether it's an empty shell or a loaded shell, it's considered part of a weapon and unsafe," McGivern said. "We have students who don't know the difference. The policy is, let's be unequivocal about it. Don't bring anything like that to school. And that way they don't have to use judgment as a child." Dan Beattie and his son found the shotgun shell as they cleared out a wall of their Carlisle farmhouse, which they are renovating. Beattie, a church pastor, said he used the encounter to teach Matthias about guns and safety. He then let Matthias add the shotgun shell to his collection of raccoon bones and other farm finds. "He thought it was cool," Dan Beattie said. The Beatties said they didn't know the shotgun shell was in Matthias' pants pocket when they dropped him off last week at his public school class. "It was an oversight on my part," Dan Beattie said. The shell fell out of Matthias' pocket as he jumped around in the gymnasium, his mother said. Odds that a dropped shotgun shell would explode are "one in a million," one weapons expert says. John Underwood, an agent in the Des Moines office of the federal Bureau of Alcohol, Tobacco, Firearms and Explosives, said the odds escalate when the shotgun shell primer detonates — usually from being slammed against an object. "The danger is remote, but it's there," Underwood said. Dahm's e-mail shows school administrators considered more severe penalties before they settled on a one-week suspension for Matthias Beattie. The punishment stemmed from the Beatties' willingness to shoulder part of the blame, according to the e-mail. Dahm acknowledged in the e-mail that student discipline policies aren't distributed to families regularly because of printing costs. The e-mail said parents are expected to read the policy online. Dahm could not be reached for comment for this article. Charlene Beattie said the experience will be one of her son's biggest lessons. "I told him, 'Sometimes there are rules that are made that we are not aware of,' " she said. "We still have to abide by them." The incident marks the second time in four months that the Des Moines district's no-weapons policy has triggered controversy. In October, Brody Middle School officials suspended a sixth-grader who took empty shotgun shells to school to show a teacher. It also exemplifies a philosophical collision between home-school parents and public school policy. "Most of us in the home-school community know how to talk about things like that, and we move on," said Dan Beattie, Matthias' father. "The way our society has become, we're so scared of everything that could possibly go wrong and so we have such blind allegiance to policy that we obliterate common sense," he said. Guidelines: You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. You share in the USA TODAY community, so please keep your comments smart and civil. Don't attack other readers personally, and keep your language decent. Use the "Report Abuse" button to make a difference. Read more