George Zimmerman is behind bars. Six weeks after he shot Trayvon Martin, the state of Florida has been pressured, from above and below, to at least contemplate the notion that a man who killed an unarmed child might have a case to answer. He has now been charged with second-degree murder.

What follows from here has the potential to be every bit as divisive as the OJ Simpson trial and every bit as inflammatory as the Rodney King case – only this time there's a black president in an election year. Blacks and whites already understand this case differently. A recent Newsweek poll showed that 80% of black Americans thought Martin's death was racially motivated and 78% thought Obama's comments about the shooting were appropriate. The figure for whites was 35% and 28% respectively. In the caffeinated, disaggregated world of cable news and blogs, where people feel entitled to their own facts, the details that emerge will only deepen these fissures.

Given that it was political pressure that made the trial possible, it would be naive to suggest that, now Zimmerman is in the hands of the law, his fate is now merely a legal matter. The "stand your ground" law was political, as are the lax gun laws, and the issues of race that have propelled this case to international news. This is the state where the courts decided the presidency in 2000. The law is already politicised.

The Martins understand this, which is why they have been rallying the nation to their cause. Zimmerman understands it, too. That's why he was calling Fox News' Sean Hannity even as his former attorneys were struggling to get hold of him.

But that doesn't make it a show trial. Or at least in the hands of a competent prosecutor and a decent legal teams it needn't. The special prosecutor, Angela Corey, insisted: "We do not prosecute by public pressure or petition." For behind all the manoeuvrings and press conferences, there is a dead teenager who went out to the store and didn't come back. Until today, the state did not deem it necessary to pay much attention to why that should be, even though they knew who killed him."

So for the Martin family, this marks the end of the beginning. This is not justice. It is the chance for justice. But justice is not the same as conviction and conviction is no sure thing. Zimmerman is innocent until proven guilty. He has claimed self-defence under the "stand your ground" law which states that anyone who perceives a threat to their life has a right to use a weapon. To convict him, they must prove that he did not act in self-defence. That's not easy. Least of all in the glare of a global spotlight.

Zimmerman may be behind bars. But it's the law itself that should be in the dock.