The U.S. Supreme Court ruled today that the Second Amendment protects individuals' right to own a gun, not just the right of states to arm their militias. Ruling in the closely watched District of Columbia v. Heller, the 5-4 majority struck down a Washington, D.C. law making it difficult for residents to own a handgun.

In the 157-page opinion, Justice Antonin Scalia wrote that the Constitution does not allow "the absolute prohibition of handguns held and used for self-defense in the home."

The D.C. law bans handguns by making it a crime to carry an unregistered firearm and barring residents from keeping unregistered handguns in their homes. Registered guns must be "unloaded and disassembled or bound by a trigger lock or similar device," regulations that make the guns useless for self defense, according to gun-rights advocates.

Dick Heller, a D.C. special police officer, challenged the law after the city refused to let him register a handgun for home use. The district court dismissed his case, but the D.C. Circuit reversed, holding that he had a constitutional right to keep a gun in his home.

The nation's high court echoed the D.C. Circuit's decision.

The Second Amendment establishes that, "A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."

Scalia said the amendment could be rephrased: "Because a well regulated Militia is necessary to the security of a free State, the right of the people to keep and bear arms shall not be infringed."

He further dissected the language to conclude that it applied to private citizens.

"Putting all of these textual elements together, we find that they guarantee the individual right to possess and carry weapons in case of confrontation," Scalia wrote.

Justice Stephen Breyer dissented, arguing that the amendment "protects militia-related, not self-defense-related, interests." He was joined by Justices Stevens, Souter and Ginsburg. They also argued that the protections of the Second Amendment are not absolute. The D.C. gun regulations were adopted in 2001 to reduce the 25,000 guns deaths per year in the nation, 3,000 of which were accidental. Breyer cited a 2001 committee report stating that "for every intruder stopped by a homeowner with a firearm, there are four gun-related accidents within the home."

Relying heavily on statistics, Breyer determined that "the District's decision represents the kind of empirically based judgment that legislatures, not courts, are best suited to make."