The mass shooting at the Washington Navy Yard that left 13 people dead yesterday will inevitably spark fresh debate over increased gun legislation in the US.
Gun laws in the District of Columbia, where the Washington Navy Yard is situated, allow firearms to be possessed at home by those over the age of 21 who register their weapon with police, take a written exam and online safety course, and consent to background checks and fingerprinting.
Laws on gun control vary in other states, and are independent of federal firearms law, which itself is shaped by the Second Amendment to the United States Constitution, the National Firearms Act 1934, the Omnibus Crime Control and Safe Streets Act of 1968, the Gun Control Act of 1968, the Firearm Owners Protection Act 1986, the Gun-Free School Zones Act 1990, the Brady Handgun Violence Prevention Act 1993 and the Protection of Lawful Commerce in Arms Act 2005.
State level laws can vary hugely from federal law, however, with bans on assault weapons an example of how state-specific restrictions can be applied.
44 states have provisions in their constitutions similar to the Second Amendment to the US Constitution, with Iowa, California, Minnesota, New Jersey, Maryland and New York the only exceptions. In New York, however, the statutory civil rights laws contain a provision virtually identical to the Second Amendment.
Although firearms owners are subject to the laws of the state they are in, not the state in which they legally reside, several states have agreements to allow residents to carry out-of state gun permits.
Most states in the US require a person to obtain a license or permit in order to purchase or possess firearms, with the majority also demanding individual firearms are registered with the police or with another law enforcement agency
All states allow concealed weapons to be carried in public in some form, with many states also allowing unconcealed firearms in public on one's person or in a vehicle.
Some states and localities place additional restrictions on certain semi-automatic firearms that they have defined as “assault weapons”, or on magazines that can hold more than a certain number of rounds of ammunition.