Tougher gun laws restrict the freedoms of those who do practice, fervently, proper firearm safety, and leaves them helpless against those who would not abide by such laws.
And for the other side of the argument...
Tougher gun laws usually involve a waiting period to purchase a weapon. Those who do practice firearm safety already own guns and probably don't need to own another weapon instantly. And I don't see how a waiting period leaves someone "helpless."
Also, IMO, those who are fervent practitioners of firearm safety would be likely to follow any new laws. The irresponsible few who object to restrictions would most likely be the ones who would leave their guns unsecured.
The purpose of gun control is not to take guns out of the hands of responsible users, but to prevent irresponsible users from purchasing guns.
That said, I don't think gun control laws would have prevented this situation. This kid had problems.
When I was in 7th grade, a 9th grader brought a rifle to school. He was looking for the jocks that had tormented him for years. He didn't find them, luckily -- they were in the lunchroom (I was in there, too) -- but he wounded two teachers and a student, and he killed the principal.
He was fully trained in gun safety and used his own licensed hunting rifle to do the shooting.
The kid had problems. Problems that gun control laws couldn't have fixed.