WASHINGTON (AP) -- A divided Supreme Court sided with gun control groups and the Obama administration Monday, ruling that the federal government can strictly enforce laws that ban a "straw" purchaser from buying a gun for someone else.

The justices ruled 5-4 that the law applied to a Virginia man who bought a gun with the intention of transferring it to his uncle in Pennsylvania - even though the uncle is not prohibited from owning firearms.

The decision split the court along familiar ideological lines, though it has no direct bearing on the Second Amendment right to own guns. It settles a split among appeals courts over federal gun laws intended to prevent sham buyers from obtaining guns for the sole purpose of giving them to another person. The laws were part of Congress' effort to make sure firearms did not get into the hands of unlawful recipients.

Writing for the majority, Justice Elena Kagan said the federal government's elaborate system of background checks and record-keeping requirements help law enforcement investigate crimes by tracing guns to their buyers. Those provisions would mean little, she said, if a would-be gun buyer could evade them by simply getting another person to buy the gun and fill out the paperwork.

"Putting true numbskulls to one side, anyone purchasing a gun for criminal purposes would avoid leaving a paper trail by the simple expedient of hiring a straw," Kagan said.

Her opinion was joined by Justice Anthony Kennedy, who is often considered the court's swing vote, as well as liberal Justices Ruth Bader Ginsburg, Stephen Breyer and Sonia Sotomayor.

In dissent, Justice Antonin Scalia said the language of the law does not support making it a crime for one lawful gun owner to buy a gun for another lawful gun owner. He was joined by the court's other conservatives - Chief Justice John Roberts and Justices Clarence Thomas and Samuel Alito.

The case began after Bruce James Abramski, Jr. bought a Glock 19 handgun in Collinsville, Virginia, in 2009 and later transferred it to his uncle in Easton, Pennsylvania. Abramski, a former police officer, had assured the Virginia dealer he was the "actual buyer" of the weapon even though he had already offered to buy the gun for his uncle using his expired police identification to get a discount.

Abramski purchased the gun three days after his uncle had written him a check for $400 with "Glock 19 handgun" written in the memo line. During the transaction, Abramski answered "yes" on a federal form asking "Are you the actual transferee buyer of the firearm(s) listed on this form? Warning: You are not the actual buyer if you are acquiring the firearm(s) on behalf of another person. If you are not the actual buyer, the dealer cannot transfer the firearm(s) to you."

Police later arrested Abramski after they thought he was involved in a bank robbery in Rocky Mount, Virginia. No charges were ever filed on the bank robbery, but officials charged him with making false statements about the purchase of the gun.

A federal district judge rejected Abramski's argument that he was not a straw purchaser because his uncle was eligible to buy firearms, and the 4th U.S. Circuit Court of Appeals affirmed.

The Obama administration had argued that accepting Abramski's defense would impair the ability of law enforcement officials to trace firearms involved in crimes and keep weapons away from people who are not eligible to buy them.

"This is a very big and very positive decision that will save lives by keeping guns out of the hands of dangerous people," said Dan Gross, president of the Brady Center to Prevent Gun Violence.

The National Rifle Association sided with Abramski, asserting that the government wrongly interpreted the law and improperly expanded the scope of gun regulations. Twenty-six states also submitted a brief supporting Abramski's view of the law, while nine states and Washington, D.C., filed papers bolstering the Obama administration.

Scalia scoffed at the majority's reading of the law, noting that if Abramski intended to buy the gun as a gift or to use as a raffle prize, the government would consider him the true buyer.

"If I give my son $10 and tell him to pick up milk and eggs at the store, no English speaker would say that the store 'sells' the milk and eggs to me," Scalia said.

Kagan responded with her own analogy: "If I send my brother to the Apple Store with money and instructions to purchase an iPhone, and then take immediate and sole possession of that device, am I the 'person' (or 'transferee') who has bought the phone or is he? Nothing in ordinary English usage compels an answer either way."