Cho did not need a license or permit to buy a handgun in Virginia. The state prohibits gun shops from selling to various categories of individuals, such as convicted felons, subjects of domestic restraining orders, those dishonorably discharged from the military and persons convicted of misdemeanor domestic violence, but Cho was none of these, authorities said Tuesday.
Cho also did not run afoul of Virginia's limit of one gun purchase in any 30-day period because he left more than a month between his two purchases, authorities said.
Authorities say Cho did break the law by scratching off some of the serial numbers of the two weapons sometime before Monday's shooting spree in an apparent attempt to cover his tracks if the weapons were found near the scene.
In any case, it didn't work. "People think that if you just take the serial number off, then you won't be able to identify the weapon," Campbell said.
As soon as authorities reached the crime scene and secured the area, the two guns were delivered to an ATF forensic lab in Ammendale, Md. There, experts used special techniques to "raise" the serial numbers, which allowed them to contact the manufacturers to see where the guns had been shipped initially.
Authorities also found paperwork for the gun purchase from Roanoke Firearms in Cho's possession. At least four agents rushed over to the shop, where Markell produced the required federal form 4473 linking the purchase to Cho.
But the ATF still needed to trace the second gun. Its lab experts were able to get the serial number on the second weapon by 4 a.m. Tuesday. They contacted the manufacturer to learn which wholesaler had received that particular shipment of weapons. From there, authorities tracked the gun to JND Pawnbrokers, and then to Cho, the federal official said.
Gun control advocates said Tuesday that Cho's rampage underscored the need for more checks and balances over gun purchases.
"The fact of the matter is that it is too easy for any American to get their hands on the kind of firepower you need to execute 32 people in short order," said Kristen Rand, legislative director of the Violence Policy Center in Washington. "They are just much more efficient killing machines," Rand said of semiautomatics like the Walther and the Glock.
