It’s been sixteen months since an encounter between Trayvon Martin and George Zimmerman left the former mortally wounded on the rain-soaked ground of Sanford, Florida, and placed the latter on a circuitous path to the defendant’s table at the Seminole County Courthouse, where jury selection for his trial began Monday. During that time, we’ve witnessed the hooded sweatshirt transform from a utilitarian garment into a statement of political solidarity; we’ve become aware of the hazy shades of innocence created by Stand Your Ground laws in Florida and beyond. We’ve seen cable news parse audio of Zimmerman’s 911 call to determine what he had said about Martin before getting out of his car to confront him. The faces of Martin’s parents, dignified though grief-stricken, have become familiar to us, as has that of Robert Zimmerman, George’s look-alike sibling and chief defender in the media. But more than anything we have come to understand context.

It’s possible—no, reasonable—to look at Martin’s death as the opening scene in a four-act drama centering on American gun culture. The subsequent scenes were set in Aurora, Colorado; Oak Creek, Wisconsin; and Newtown, Connecticut.

If we’ve been hesitant to recognize Martin as part of that processional of slain bystanders, it’s because the public sympathies here are muddied. More than in any of the other instances, people quietly, perhaps ashamedly—or not—can find it easier to imagine themselves in Zimmerman’s shoes than those of James Holmes, Wade Michael Page, or Adam Lanza. How else to explain the impressive sums proffered by supporters via Zimmerman’s Web site? Or the nauseating popularity of Trayvon Martin shooting targets last spring? Not all unarmed citizens facing down armed men are created equal. Where Newtown, the tragic climax to a season of violence, caused deep self-reflection on the presumed bonds between weaponry and liberty and the unchallenged authority of the National Rifle Association, the Martin-Zimmerman incident prompted far less pondering about these questions. Context matters.