The deadly mass shootings in both Uvalde, Texas and Buffalo, New York have put scrutiny on the legal gun-buying age in the United States.
The gunman in Tuesday's deadly rampage at Robb Elementary School in Uvalde, which killed 19 students and 2 teachers, was 18 years old.
The suspected shooter at the Tops Friendly Market in New York's Buffalo city, where 10 people were killed, was also 18.
Both men were legally able to buy their AR-15 style rifles under the Gun Control Act of 1968, which allows individuals 18 or older to purchase shotguns and rifles.
The Texas shooter also used a handgun, which according to the Gun Control Act, can only be sold to individuals 21 or older.
"What in God's name do you need an assault weapon for unless to kill someone?" said US President Joe Biden after Tuesday's deadly mass shooting in Texas.
AR-15 style rifles are lightweight semi-automatic weapons originally created for the US military, but have become popular among civilian gun enthusiasts, with more than 20 million AR-15-style rifles legally circulating in the US.
Biden is calling for "commonsense" gun laws, claiming that after the assault weapons ban was passed in 1994, mass shootings went down, but after the law expired in 2004, Biden said "mass shootings tripled."
The AR-15 rifles range from $400 USD for a basic model to $2,000 USD or more for higher-end models. The powerful, military-grade weapons also have a feature that prevents ammunition jams so the shooter can keep shooting.
In a state like Texas, anyone can openly carry rifles in public without a permit. The Uvalde shooter had two AR-15-style rifles that were perfectly legal.
Biden and Democratic lawmakers are pushing for stricter gun control measures like universal background checks and renewing the Federal Assault Weapons Ban, but the measures have been blocked in recent years in a narrowly divided Senate, with Republicans opposing those stricter rules.
"As a nation, we have to ask, when in God's name are we going to stand up to the gun lobby?" said Biden. "We have to act. Don't tell me we can't have an impact on this carnage."
