The only answer to your question is total gun control. That might have prevented this.
Nevertheless, It wouldn't have prevented someone like me who knows chemistry from binding together some legally purchased acetone peroxide and blowing the place to pieces.
So currently peroxide is as big a problem as gun violence? Just another rationalization.
Nosomo, I think the point is, take away guns and it or something else will become a problem. The gun is only a tool utilized by a much larger issue. if you don't have a gun and you want to kill yourself, you'll still kill yourself. yes a gun is an easier way to do it, but lack of one is not going to stop you. if you don't have a gun and you want to kill someone, you're going to kill them regardless. again, the gun makes it easier, but you'll still do it without a gun.
The problem is our society is people do not value life. we have developed a pervasive attitude among many that if some one slights you, you kill them. a few decades ago, if someone slighted you, maybe you beat them up. thats the problem we have to fix. we also have to stop turning a blind eye to mental health issues. they are ou there, but we don't want to deal with them. and this killing is a perfect example. all the signs were there. how does this guy get security clearance to a sensitive naval area? especially when he had issues in the service. especially when he had priors involving weapons. especially when the Rhode Island Police warned the Navy, this guy was a potential issue. but nothing is done at all. a gun is only a tool this existing problem used. and how does a guy with all of these issues and red flags get through a security checkpoint, with metal detectors, carrying guns and ammunition. there are so many things gone wrong here. the gun was nothing more than the tool used. and honestly, when you look at the number of guns in the USA only .000036 of them ever kill anyone.