Connor Betts was dressed in what appeared to be tactical gear when he opened fire in Dayton, Ohio, early Sunday.
In surveillance video released by police, the 24-year-old can be seen wearing a bulletproof vest, a mask and ear protection.
Shockingly, body armor like that is readily available to anyone online, where bulletproof vests can go for $185, ear protection is as low as $20 and a mask can be purchased for just $10.
They're also available at retail stores like Blueline Tactical and Police Supply in Elmsford, New York.
Despite wearing all that body armor, Dayton cops swiftly brought Betts down in under 30 seconds. Still, he managed to kill nine people in that time.
Inside Edition spoke with Blueline CEO Ben Rosenshine, who explained that Betts was killed despite all that armor because it “only protects a certain portion of his body.”
He added that “we don't know the quality of what he was wearing."
"My guess for a young person who is planning on doing something like this, they were buying it from the internet," he said.
Rosenshine said that the most vulnerable spots, even with body armor, are the throat and groin areas, which are not protected by a vest. The shooter's face and head were also exposed.
Body armor has been used before in other massacres, as well, like the movie theater shooting in Aurora, Colorado, in 2012 that left 12 people dead. Just last week, the gunman who killed three people at the Gilroy Garlic Festival in California also wore tactical gear.
Now, some are asking why individuals outside law enforcement should be allowed to own body armor.
"Buying body armor is no different than buying a fire extinguisher. Basically you've got it there in the hopes that you're never gonna use it, it's an insurance policy for honest, law-abiding citizens, but almost anything can be used for a nefarious purpose no matter what it is,” Rosenshine said.