When you see a powerful 9mm semi-automatic pistol in action, you begin to understand how one man could kill so many innocent people in a short time.
News that a weapon like this was used in the Virginia Tech rampage comes as no surprise to Armando Fontoura, sheriff of Essex County, N.J. "When you go into a classroom, how many kids that were there, this is like shooting fish in a barrel. They are there and they are at your mercy," Sheriff Fontoura explains.
A Glock 19 is easily obtained in states like Virginia, where Cho Seung-Hui purchased one last month. "We turn down gun sales every day literally, there are so many sales we turn down to air on the side of caution, but this just looked like a clean cut young man," gun shop owner John Markell tells correspondent Erin Moriarty.
Markell owns Roanoke Firearms, a shop a little over 30 miles from the Virginia Tech campus. "He was not nervous at all in purchasing the gun. He had knowledge of the gun, just a typical sale, nothing out of the ordinary," Markell remembers of his interaction with the shooter.
After showing a government issued photo ID – his green card – and a driver's license to prove his Virginia residency, Cho Seung-Hui charged $571 on a credit card and walked out of Roanoke Firearms with a new 9 mm Glock 19 and 50 rounds of ammunition.
Click here for an interactive gallery of the victims.
"If we see a resident alien with a credit card, it's usually a good indication that they're a good upstanding citizen, not someone who would go on a shooting spree," Markell says.
And Markell tells Moriarty an instant background check showed nothing. "It went straight through. We did the state police check with federal computers. It came back clean. No drug convictions, no felonies, domestic violence," he explains.
The 9mm, says Sheriff Fontoura, is easily concealed and easy to use and most young men are familiar with one. "Have you been to the movies lately? When you see the gunfire, most likely the weapon is a 9mm," he explains.
Movies like the Matrix are just one example; the 9mm also has a starring role in video games and music. "It's a sexy weapon," Fontoura says. "It just looks good. And our young people are enjoying that and learning from that."
It may help to explain why so many mass shootings involve a 9mm weapon —both of the Columbine shooters were armed with one.
But it's not just the gun that can turn a shooter into a mass killer. It's also the size of the magazine or clip that contains the ammunition that allows a shooter to fire several rounds without having to reload.
"Now when the clip comes in, you just kick it out, grab another one, kick it in and your are ready to go again," the sheriff explains.
Asked how long it takes to reload, Fontoura says, "If you are really go at it, you can do it in a matter of seconds."
Cho was able to fire 15 rounds at a time, one by one, before he would stop and reload. He was also armed with .22 caliber semi-automatic handgun that shoots 10 rounds at a time.
"Obviously he had plenty of practice because he would have had to change magazines quite frequently," says Markell. "He must have had a least half a dozen magazines with him."
The death of 32 people yesterday is sure to re-ignite an old debate.
"I see no reason to blame the gun," Markell argues. "The fault goes squarely on Mr. Cho. No one else. Nothing else. If he didn't have that Glock he would have done it with something else."
"These are instruments of death…that's what they are. Guns are instruments of death. They're not for any other purpose," Fontoura says. "And we need to remember that."