Last month's shocking shooting at Virginia Tech - the nation's deadliest, with 33 killed - is likely to have lasting repercussions. Already bills are pending in state legislatures to allow or ban concealed weapons at state colleges, and efforts are under way to bolster campus security.
These changes echo what took place after two student killers stunned the country with a rampage eight years ago that left 15 dead at Colorado's Columbine High School.
In the wake of the Columbine shootings, state lawmakers passed anti-bullying laws and sought to curb minors' access to violent video games. Law enforcers changed how they respond to shootings in progress. Most states now require schools to draw up crisis plans in case of emergency, sometimes in conjunction with local law enforcement, and some states began requiring lockdown drills.
States already had stringent laws against weapons at school. But after Columbine, harsher punishments were levied for bringing weapons to school, and states clarified that "school property" where weapons were banned included parking lots, off-campus school events, buses, and sometimes even school bus stops.
Some states even elaborated what types of weapons were banned: blunt-bladed table knives in Florida, razor blades in Georgia, and BB guns and Tasers in Virginia.
And schools beefed up their standards of conduct, resulting in more expulsions and suspensions for bad behavior.
The post-Columbine period also saw a rise of programs meant to provide a more nurturing school environment. "There was an emphasis on teachers and students building relationships together," said David Griffith of the National Association of State Boards of Education
. "If you can … make all these children feel secure and wanted and not alienated, you can kind of avoid these problems."
Since Columbine, several states have enacted laws to require or encourage conflict-resolution and violence-prevention programs in schools.
One theory behind these efforts is that students who trust their teachers are more willing to report rumors of impending violence. According to a 2002 report
by the U.S. Secret Service and the U.S. Department of Education that studied 37 school shootings, in 59 percent of the cases, more than one person - usually other students - knew about a potential shooting but did not tell any adults.
In the 2001 shooting at Santana High School in Santee, Calif., the shooter's friends knew what was likely to happen. They even "tried to pat down their friend, but they didn't feel confident in the adults to go and say something," said Dave Osher of the Center for Effective Collaboration and Practice
, which promotes child welfare.
The Secret Service study also found that 71 percent of the school shooters had felt bullied or persecuted in school, including the Columbine killers. That led state legislators to take on the high school social strata with anti-bullying laws.
Before Columbine, only three states had laws to curb school bullying, usually by defining harassment and setting up policies to deal with it. Now at least 32 states have such laws, and since last year four states - Arkansas, Idaho, Iowa and South Carolina - have enacted laws to stop online bullying at social networking sites such as Myspace and Facebook.
State efforts didn't stop at the schoolhouse, either. Columbine's shooters were obsessed with violent first-person shooter video games like "Doom." Since the shooting, 13 states passed regulations aimed at making it tougher for minors to play violent video games, although some were blocked by courts.
Law enforcement also saw huge changes in how it responds to a shooting. Before Columbine, police protocol was to contain the area and wait for a SWAT team. During the Columbine shooting, police waited almost 20 minutes before forming a makeshift SWAT team to enter the school, and it was still hours before law enforcement made a thorough sweep. During the wait, the shooters continued their bloodbath and an injured teacher bled to death.
Now police are expected to engage as soon as possible if a shooting is ongoing, even if the SWAT team isn't there yet.
But there was one area where Columbine's effect was mixed: controlling access to guns. The months after the massacre saw legislators kill bills that would have expanded access. California limited handgun sales to one a month, a move opponents and supporters alike said would not have happened if not for Columbine.
In 2000, voters in Colorado and Oregon approved initiatives to require background checks at gun shows. The federal Brady bill mandates such checks by licensed gun dealers, but left a loophole for gun shows. A friend of the Columbine killers bought them two guns at a gun show that they later used in the killings.
But post-Columbine gun-control efforts are exemplified by the fate of a Colorado bill to allow permit holders to carry concealed weapons. Hours after the shooting, the bill's sponsor quietly tabled it. Four years later the same bill breezed through the Legislature, and today only two states - Illinois and Wisconsin - don't allow permit holders to carry concealed weapons.
"Right after Columbine, many states at least gave lip service to doing things," said Sam Hoover of the Legal Community Against Violence
, which favors tighter gun control. "But as always happens, even though there's a lot of media exposure, it's more talk than actual action on the part of legislatures."
The question now is what kind of lasting change will come from Virginia Tech. Colleges already have begun adding text-messaging alert systems to warn students of emergencies, and eight governors have convened college security task forces.