The Second Amendment states “…the right of the people to keep and bear arms shall not be infringed”.
Yet a string of massacres has led to calls for the constitution to be amended so that atrocities like Sandy Hook, Columbine and San Bernardino can never be repeated.
The US, which has less than five per cent of the world’s population, has up to 50 per cent of the world’s civilian-owned guns. It also has the highest homicide-by-firearm rate among the world’s most developed nations.
Sunday night’s attack was the 273rd mass shooting in the country this year according to Gun Violence Archive, a website that tracks incidents and crimes involving guns across the United States. A “mass shooting” is defined as four or more people being shot at the same time or location.
Federal law sets the minimum standards for firearm regulation but individual states have their own laws and it is legal to openly carry firearms in some.
California, Florida, Illinois and the District of Columbia generally prohibit people from openly carrying firearms in public.
New York and South Carolina prohibit openly carrying handguns, but not long guns, while Massachusetts, Minnesota, and New Jersey prohibit openly carrying long guns, but not handguns.
Thirty one states allow the open carrying of a handgun without any license or permit, although in some cases the gun must be unloaded. Fifteen states require some form of license or permit in order to openly carry a handgun.
Nevada has some of the least stringent gun laws with people allowed to carry weapons without registering as a gun-owner.
Background checks are made when people buy guns.
Incredibly, the state does not ban assault weapons, automatic or semi-automatic firearms, and there are no limits on buying ammunition.
Atrocities like the Sandy Hook school shooting in 2012 when 20 young children and six teachers were slain has led to calls for tougher controls on access to firearms.
Failure to crackdown on gun control prompted reality TV star Kim Kardashian to issue a statement on National Gun Violence Awareness Day this year.
She said: “In almost 20 years, our country has made very little progress in enacting laws that would help protect innocent Americans from people who should not have access to firearms.
“There are more guns owned by civilians in this country than in any other country.”
“President Trump actually signed a bill revoking a regulation recommended by President Obama that would have added 75,000 names of people with registered mental illnesses to a national background check database. This is crazy.”