The failure isn't in gun laws.
The failure is on local law enforcement & FBI for not following up on a well known potential threat that had been reported numerous times. They should have taken some lessons from this story that happened just a day or two before. Thankfully our law enforcement did follow up and stop an even greater tragedy from happening.
Grandmother foils alleged school shooting plot in Washington state
We need a holistic solution to this problem. You can never stop a nut from killing people but maybe if all they could buy was 10 round clips then maybe instead of 17 people killed it would only be 10. That solution right there will save lives. No question about it. So why do Republicans insist on being able to have 20 round clips? Don't answer that. I know why. It's because they want the most powerful gun they can get their hands on. Well guess what? From now on the most powerful guy you can get only holds 10 rounds.
And if you have a 20 round clip, keep it. It used to be worth $1000 but now it's worth $2000 because they don't make them anymore. If I owned a 20 round clip and they stopped making them, I'd be happy. Just made my gun more valuable. But in 2 or 10 or 20 years, American citizens can only purchase 10 round clips.
Very simple.
Next, register every gun. No you can not buy a gun at a gun show. You can purchase it but it will be about a month before you can pick up your gun, from the police station.
Americans get to vote on this in November. Doesn't matter what you or I think. Lets see what the voters think.