If you’re cheering on the charges brought against Colin Gray, the father of our nation’s latest school shooting suspect, it’s worth asking yourself how, exactly, he broke the law.

His 14-year-old son, Colt Gray, has been charged with opening fire at school on Wednesday, killing four people. The assault-style rifle he was accused of using was reportedly a Christmas gift from his dad.

But the Grays live in Georgia, where giving your son an AR-15-style rifle is not, in itself, a crime. (The laws appear to be stricter about handguns.) Nor does Georgia have a law requiring Mr. Gray to safely lock away his guns. Georgia is notorious for having some of the weakest gun laws in the country.

Mr. Gray rocked back and forth in shackles and prison stripes on Friday morning as the charges against him were read. His son had just been charged with murder for opening fire at Apalachee High School, killing two students and two teachers. Next came the charges against the white-haired Mr. Gray, including second-degree murder and involuntary manslaughter for allowing his son access to the gun even though, prosecutors say, Mr. Gray knew the boy was a threat to himself and others.

Now father and son are both sitting in jail.

The United States, desperate to stop mass shootings, has been seized by an increasing zeal to prosecute parents. Jennifer and James Crumbley, convicted of involuntary manslaughter this year in Michigan after their son’s school shooting, hadn’t broken any gun laws, either. Prosecutors introduced lurid testimony about their personal lives and hobbies in trying to convince a jury that the Crumbleys were indifferent to their son’s mental health. When they were found guilty, many Americans were pleased.

These prosecutions satisfy the public desire to blame somebody. If you don’t like guns, shaming and punishing the parents feels like landing a righteous blow against gun culture. If you do like guns, it’s a bit like the predictable invocation of mental health by politicians — diverting attention from the weapons themselves and suggesting, instead, that the problem is a few bad apples among the owners. Most insidiously, though, these prosecutions set a murky legal precedent for questionable parenting while camouflaging the abject failure of the federal and state governments to adequately regulate gun safety and stop mass shootings.