"Because of the Aurora, Colorado tragedy, the American Congress must review its mistaken legislation on guns. It kills," Calderon said.
Calderon has been a frequent critic of American gun laws. During a 2010 address before a joint session of Congress, the outgoing Mexican president urged Congress to reinstate the assault weapons ban that expired in 2004.
“I fully respect, I admire the American Constitution. And I understand that the purpose of the Second Amendment is to guarantee good American citizens the ability to defend themselves and their nation,” Calderon said. “Many of these guns are not going to honest American hands, instead, thousands are ending up in the hands of criminals."
On Sunday, Sen. Dianne Feinstein (D-Calif.) also tied the Colorado shooting to a push to re-authorize the bill.
"Weapons of war don't belong on the streets," Feinstein said on Fox News. "This is a powerful weapon, it had a 100-round drum; this is a man who planned, who went in, and his purpose was to kill as many people as he could in a sold-out theater. We've got to really sit down and come to grips with what is sold to the average citizen in America.”
Rep. Ed Perlmutter (D-Colo.), the congressman who represents Aurora, also urged for a reinstatement of the assault weapons ban.
But Sen. Ron Johnson (R-Wis.), appearing alongside Feinstein, said such legislation would do little to curtail mass killings and instead would "reduce America's freedom."
"I don't think society can keep sick demented individuals from obtaining any type of weapon to kill people," Johnson said. "This isn't an issue about guns, this is really just an issue about sick, demented individuals."