When 17-year-old Austin Wyatt Rollins opened fire in Maryland’s Great Mills High School, he did so with a firearm he was prohibited from purchasing.

Investigators are now trying to ascertain how Rollins acquired the gun.

The NRA-ILA lists gun laws by state, and that list shows that Maryland law requires the purchaser of a handgun to be 21 years of age. (Federal law also requires that handgun purchasers be 21 years of age.)

Moreover, Maryland gun controls put in place in 2013 require would-be handgun buyers to submit fingerprints to the state police beforehand. The Baltimore Sun reports that would-be handgun purchasers must also undergo training. pay a fee to acquire a handgun license, and go through a seven-day waiting period before being allowed to acquire a handgun, even if they are of age to do so.

Yet the 21-year age requirement, fingerprint requirement, fees, and licensing requirement, and sseven-day waiting period did not prevent 17-year-old Rollins from having a Glock 9mm pistol Tuesday morning.

He used that handgun to injure two people before being confronted by an armed school resource officer. The officer shot one round at Rollins, who fired one round in response. Rollins was later pronounced dead and investigators are working to determine if he was killed by the resource officer or if he took his own life.

AWR Hawkins is an award-winning Second Amendment columnist for Breitbart News, the host of the Breitbart podcast Bullets with AWR Hawkins, and the writer/curator of Down Range with AWR Hawkins, a weekly newsletter focused on all things Second Amendment, also for Breitbart News. He is the political analyst for Armed American Radio. Follow him on Twitter: @AWRHawkins. Reach him directly at awrhawkins@breitbart.com. Sign up to get Down Range at breitbart.com/downrange.