After the Las Vegas gunman rained down rapid fire terror on defenseless concert goers --many question how Stephen Paddock got his hands on what seemed to have been a fully automatic rifle.
Federal gun laws make buying those rifles extremely difficult. The application process is slow and pricey.
"There are not many people licensed to even sell them," said Donald Dawkins. "You just can't walk into a gun shop and get a fully automatic weapon. It's not like that, you can't do that."
Dawkins is a retired ATF agent.
"To apply for a license, that process is very lengthy. If he had no red flags, he might have received it but I doubt if he did that," Dawkins said.
But former ATF agent and spokesperson Donald Dawkins says there are ways to convert a semiautomatic modern sporting rifle that shoots only as fast you can pull the trigger, into a weapon capable of rapid fire.
"You can go online and unfortunately find ways to modify it," Dawkins said. "Sometimes you'll be successful and sometimes not. There are instructions online with how to do it."
And then there are legal accessories gun owners can buy like the slide fire stock, which gives semi-auto rifles, fully auto capabilities.
Right now it's unclear what, if any method Paddock used. Although Dawkins cannot speak to the specifics of the case, he's confident investigators will get to the bottom of it.
They found several rifles in paddock's hotel room. At least two of those rifles were chambered for the common .223 and the larger .308 caliber rounds.
Dr. Steve McGraw, chief of St. John Providence Hospital's ER department, explained the damage those rifle rounds can do to the human body.
"The tissue loss is massive," he said. "The internal damage is much worse than what you appear to see on the body. What looks like a relatively small hole can have a catastrophic amount of injury inside the body. Multiple organs can be injured or destroyed at the same time."
There were no red flags when Paddock purchased the firearms from two Nevada shops earlier this year. He reportedly passed the background checks. Dawkins said the ATF will trace the guns in Paddock's hotel room and also see if he modified them illegally.