The Los Angeles Times reported on Thursday that Syed Rizwan Farook — one of the gunman in the mass shooting last week in San Bernardino, California — asked a friend, Enrique Marquez, to buy the two AR-15 semi-automatic rifles he later used to kill 14 people and injure 21 others. At first glance, Marquez’s actions were a textbook “straw purchase,” in which a person buys a gun for someone else — usually someone who cannot pass a background check. For that reason, straw purchases are prohibited by federal law. Farook, it turns out, could have passed a background check, and was not prohibited from owning a firearm — in fact, he bought two pistols on his own. A source told the Times that Farook wanted Marquez to buy the rifles because he “didn’t want the guns tied back to him.”

The revelation highlights a wrinkle in a more than 50-year-old gun law: If you buy a gun for your friend, and your friend is legally allowed to have that gun, is that purchase against the law?

It’s a question the Supreme Court addressed last year in a case called Abramski v. United States. Bruce Abramski, a former Virginia police officer, purchased a Glock 19 pistol in November 2009 for an uncle living in Pennsylvania, using his law enforcement discount. After buying the gun in Collinsville, Virginia, Abramski drove it up to his uncle’s town in Pennsylvania to pass off the firearm at a licensed gun dealer, as state law requires. (Other states, like New York and Oregon, have similar laws that require private transfers of guns to be executed through licensed dealers.) His uncle would have passed a background check — but he would not have been eligible for the lower price that Abramski was charged, a savings that he passed along when reselling the gun to his relative.

A year later, federal officials indicted Abramski for lying on his background check form at the gun store in Collinsville. The Form 4473 asks each purchaser, “Are you the actual buyer?” Abramski answered, “Yes,” even though he knew he was buying the gun for someone else.

Five of the nine Supreme Court justices thought Abramski made an illegal straw purchase. Justice Kagan, who wrote the majority opinion, said that the law prohibiting straw purchases has two goals. One is to prevent guns from falling into the hands of people who should not have them. The second is to make it easier for law enforcement officials to trace crime guns. As Kagan notes, a legal straw purchase would make identifying the origins of such guns notably more difficult, and enable criminals to “always use straw purchasers to evade the law.”

Justices Scalia, Thomas, Alito, Chief Justice Roberts, and the National Rifle Association did not agree with the the court’s majority. They argued that the sole purpose of the federal government’s straw purchase rule was to prevent guns from going to buyers who could not pass background checks: “Congress’ intent was not to prevent transfers of firearms between persons who are both legally entitled to purchase the firearm.” But Justice Kagan notes that if the straw purchase rule worked so narrowly, “many would-be criminals … could use straws to purchase an endless stream of guns off-the-books.”

Her point is illustrated by the San Bernardino shooters. There is nothing in Farook’s criminal records that would have prevented him from passing a background check. So does it matter that he got two guns through a friend? According to the Supreme Court, it does: Because five of the nine justices signed Justice Kagan’s opinion, the law says Marquez is an illegal straw purchaser. But the victory was narrow — just one vote would have paved the way for legal straw purchasing.

The decision in Abramski is a reminder of how difficult it is to predict the Supreme Court’s rulings on guns. In fact, the case that sealed the Second Amendment as an individual right came down to a 5-4 vote. But in the next four years — when as many as four new Supreme Court justices are expected to take the bench — these margins could swing in either direction.

[Photo: AP/Chris Carlson]