The accidental shooting of Arizona firearms instructor Charles Vacca by a 9-year-old girl, who he was teaching to use an Uzi machine gun, has renewed a debate in the United States about training children to handle guns. In the wake of the killing, social media erupted with comments from both sides of the debate.

Charles Heller, a media coordinator for the gun-rights group Arizona Citizens Defense League, told Mashable that there should be no age restrictions when it comes to children using firearms

"If they can reason between right and wrong, and they can follow directions and they have the physical capabilities, then it's OK,” he said.

The National Rifle Association, the nation's most influential firearms pressure group, attracted criticism for tweeting Wednesday about new ways children could “have fun” at shooting ranges. 

Conversely, the Associated Press quoted Gerry Hills, the founder of Arizonans for Gun Safety, a group seeking to reduce gun violence, as saying: "We have better safety standards for who gets to ride a roller coaster at an amusement park. I just don't see any reason in the world why you would allow a 9-year-old to put her hands on an Uzi." 

And Arizona Republic columnist E.J. Montini asked, “Why would a shooting range allow a kid to handle an automatic weapon? Why would a parent? And, most importantly, why would a state?” 

Sam Scarmardo, the manager of the Last Stop shooting range, where the incident took place, told the BBC that “the criteria [for being allowed to shoot an Uzi] is 8 years old... We instruct kids as young as 5 in .22 rifles.”

According to Mashable, the range will now institute a new policy preventing children under the age of 12 from handling such weapons.

The Wall Street Journal reports that gun usage is a sensitive topic in Arizona, which has strong laws supporting gun rights, and it isn't unusual for families to shoot together at ranges. 

Despite the polarized debate, however, even some pro-gun commentators felt that 9-year-old children are too young to be allowed to handle an automatic weapon.

Gun enthusiast Todd Watkins of Atlanta, who told BBC News that he owns 112 guns, said, “For me, the issue is that this child was firing an automatic weapon. I would not have my child training with automatic weapons. Automatic firearms are harder to control.” 

In addition, Scarmardo told the New York Post: “I have regret we let this child shoot, and I have regret that Charlie was killed in the incident.”

CBS News reports that there is no requirement in Arizona for shooting-range employees to be certified as firearms instructors. The National Rifle Association said Charles Vacca was not an NRA-certified instructor.