news.bbc.co.uk/2/hi/americas/7302179.stm (external - login to view)
The United States Supreme Court is hearing arguments in a landmark case about the country's gun laws.
It is the first time in nearly 70 years that Americans' right to keep and bear arms is being debated in court.
The nine justices will decide whether to uphold or overturn the handgun ban in Washington DC, but their decision could have a national impact.
A ruling is expected by the end of June, and may well become an issue in November's presidential election.
As the session began, several dozen demonstrators supporting opposing sides of the gun law argument gathered outside the Supreme Court building.
Washington DC has some of the strictest gun control laws in the United States.
Since 1976, there has been a ban on the private possession of handguns in the capital, as well as a requirement to have rifles or shotguns locked or dismantled.
These rules are now being challenged by a federal building security guard, Dick Heller.
He argues that if he is allowed a handgun at work, he has a constitutional right to have one at home for self-defence.
DC city council argues than the ban is justified because "handguns have no legitimate use in the purely urban environment of the District of Columbia".
The debate, which has raged for many years, is centred on whether the Second Amendment of the US Constitution protects an individual's right to possess guns, or simply a collective right for an armed militia.
The case before the Supreme Court is being closely watched and has attracted dozens of briefs from outside groups arguing their point of view.
"This may be one of the only cases in our lifetime when the Supreme Court is going to interpret an important provision of our Constitution unencumbered by precedent," Georgetown University law professor Randy Barnett told the Associated Press.
The country - including the Bush administration - is split on the issue.
US Solicitor General Paul Clement has argued that while individuals may have the right to own a gun, they are still subject to reasonable government intervention.
Others, including Vice President Dick Cheney and John McCain, the presumptive Republican presidential nominee, are urging the court to take a stronger stand in favour of gun rights, and overturn the Washington ban.
Organisations also backing gun rights include groups as diverse as Pink Pistols and Gays and Lesbians for Individual Liberty, Jews for the Preservation of Firearms Ownership, as well as the powerful gun lobby, the National Rifle Association (NRA).
"More anti-gay hate crimes occur in the home than in any other location," the Pink Pistols argued in their brief to the court, arguing that guns should be allowed in the home for self-defence.
The groups on the other side of the argument include law enforcement agencies, the American Bar Association, and coalitions against domestic violence.
They fear that easing access to handguns will lead to a rise in murder rates.
"Women are killed by intimate partner, husbands, lovers, ex-husbands or ex-lovers, more often than by any other category of killer," said the National Network to End Domestic Violence.
BBC Washington correspondent James Coomarasamy says that the Supreme Court's ruling could have reverberations across the US.
But other's differ of course, so this should be interesting