He added that, if teachers or others in schools were armed, it could help stop school shootings.
"Had somebody in that room had a gun, the result would have been better," he said of the recent campus shooting in Oregon. "I think that if you had the teacher, assuming they knew how to use the weapon, which hopefully they would, you would've been a lot better when this maniac walked into class, starting to shoot people."
"This isn't a gun problem; this is a mental problem," he told CNN. "It's not a question of the laws; it's really the people."
"Guns, no guns—it doesn't matter," Trump said on NBC's "Meet the Press" recently. "You have people that are mentally ill. And they're going to come through the cracks. And they're going to do things that people will not even believe are possible."
"No matter what you do, you will have problems," Trump told ABC's George Stephanopoulos. "And that's the way the world goes."