These past 12 months have had such a significant number of shootings that many of us have forgotten about Trayvon Martin. Tuesday marks the anniversary of his death.

Since that time, many more Americans have died because of gun violence, and the way we talk about gun violence has changed radically.

When George Zimmerman, a white Latino man patrolling his neighborhood, shot Martin, a black teenager who was unarmed, race became the central focus of our nation’s thoughts about gun violence.

We saw a white man shooting an unarmed black teenager, whose only crime appeared to be wearing a hoodie. Debates ensued about who did what and whether Martin was as innocent as he first appeared. But every debate was tinged with the specter of race.

Since Martin died, America has witnessed mass shootings in Colorado, Wisconsin and Connecticut. Except for the shooting at the Sikh Temple in Wisconsin, race didn’t factor into the media’s conversation.

Instead, the conversation centered on mental illness.

Questions were asked about the mental health of the shooters, and many wondered whether we should tailor gun laws to exclude the mentally ill. The discussion centered around mental illness even though little is known about the mental history of these mass shooters. People assumed that to kill 20 school-age children, the Newtown mass shooter had to be mentally ill.

But the issues surrounding gun violence are more complicated than that.

After every incident, lawmakers and journalists asked whether we need stricter gun laws. This is a natural response to these public shootings, but these questions should be the norm, not the exception. This country needs to constantly re-evaluate how it views gun restrictions and availability.

More than 500 people were killed in Chicago last year. That statistic gets thrown around a lot lately, but it’s a reminder that more people were killed with guns in Chicago in 2012 than were killed in mass shootings. Most of those shootings didn’t receive any media attention, aside from the small three- or four-paragraph news brief on a website.

That’s why we can’t wait around for tragedy to strike. We can’t wait for several people to be killed at one time in one place. We can’t wait for a white man to shoot an unarmed black teenager. Gun violence is endemic. It happens so often that we rarely consider it except in the most appalling cases.

If we want to see meaningful change in this country, we have to actively seek that change all the time.

Gun violence in this country is a complex issue. We can’t narrow the problem down to just race or mental illness. When tragic shootings occur, multiple factors are at play. Instead of trying to pigeonhole each shooting into one category, we should recognize that these shootings have complex roots. No one change in gun laws will stop them.

This anniversary is not only a time to remember the death of Trayvon Martin, but also a time to consider how little has changed.