"This was no spur of the moment crime. He's been thinking about this since at least the time he bought the first gun," said former FBI agent Brad Garrett, an ABC News consultant.
Both guns were bought in Virginia, according to the officials.THE BLOTTER RECOMMENDS
Under Virginia law, state residents can only buy one handgun in any 30 day period, suggesting Cho bought his second weapon after April 13, or sometime over the weekend.
"He clearly spent some time figuring out how he was going to take care of business once classes began on Monday morning," said Garrett.
The date of the first gun purchase will likely serve as the time of "some triggering mechanism that was very important" to Cho said Garrett, an expert on profiling murderers.