In order to shoot 10 people dead and wound 10 others, teenager Dimitrios Pagourtzis opened fire Friday as the school day began in the town of Santa Fe with a shotgun and revolver legally purchased by his father.

Texas Governor Greg Abbott, a Republican, focused on the need to better address mental health issues and to arm school personnel, rather than calling for limits on the proliferation of legal weapons.

This vast and conservative southern state has among the most permissive firearm laws in the United States, a country where a third of children live in a household with at least one firearm.

Any buyer as young as 18 can buy a firearm in Texas without a special permit, including for semi-automatic, rapid-fire weapons with large-capacity magazines.

- Pulling the trigger -

Paradoxically, buyers must be 21 in order to purchase a handgun. A permit is required to carry this type of weapon, and more than a million Texans have the document.

Federally accredited weapons dealers rely on a cursory search for any red flags in a potential buyer's documented mental medical history or potential criminal record. The process itself can easily be avoided through online purchases or at traveling fairs.

It's also legal to openly carry a shotgun or rifle, except where it is expressly forbidden.

Texas played host to the National Rifle Association's annual convention earlier this month.

At the event President Donald Trump proclaimed his support for the powerful gun rights lobby that provided major financial support to his 2016 presidential campaign.

During primaries in March, arms control legislation was not a major topic in either the Democratic or the Republican camp.

Some Republican candidates make their support for gun rights a major plank of their campaign. In a 2015 video, Texan Senator Ted Cruz cooked bacon wrapped around the barrel of his assault rifle by firing the weapon.

- Children as 'collateral damage' -

But the state's gun culture has a price. Since January 2009, Texas has seen at least 20 shootings with four or more people killed -- gunman not included -- according to the group Everytown for Gun Safety. That's a national record.

Six months ago, a man opened fire at a church near San Antonio, killed 25 people, including a pregnant woman.

"Our children have become collateral damage in a nation that allows its gun laws to be written by gun lobbyists," said Shannon Watts, founder of Moms Demand Action for Gun Sense in America.

Studies show that two thirds of children know exactly where their parents hide their weapons, even when adults are convinced otherwise.

In more than 40 percent of households with weapons and children, at least one weapon has no engaged safety mechanism or is located in an unlocked space, according to a 2000 study by the American Journal of Public Health.

Some 1.69 million children under the age of 18 live in a hone with at least one loaded and freely accessible weapon, the American Academy of Pediatrics found in a 2005 study.