U.S. Attorney General Eric Holder (Tim Boyles/Getty Images); George Zimmerman (Gary W. Green/Pool/Getty Images)

(The Root) ‚ÄĒ If the state of Florida's prosecution of George Zimmerman was an uphill battle, any Department of Justice effort to prove that he violated Trayvon Martin's civil rights would face the legal equivalent of Mount Everest.

The federal government faces intensifying pressure to indict the former neighborhood-watch volunteer on civil rights charges that he shot and killed Trayvon because the unarmed boy was black. Attorney General Eric Holder has said he is "concerned" and promised that the Justice Department would "consider all available information" before deciding whether to prosecute.

The 1 million people who signed an NAACP petition urging Holder to take action shouldn't hold their breath.

In federal court, there may be no case more difficult to prove than a racially motivated crime. The government must meet the highest standards of proof that exist in American law. No wonder federal prosecutors indict criminal civil rights cases only if the evidence is a slam dunk. The killing of Trayvon, despite the justified outrage, is anything but.

The Justice Department has resumed an investigation it halted last year to allow for the state trial. The agency has long used federal civil rights law to try defendants acquitted in state courts, one of the most memorable examples being the Rodney King case.

Advertisement

Demonstrators, civil rights leaders and others are pleading for federal action to make amends for Zimmerman's acquittal on state charges. Theories abound that the feds could have a strong case. Huffington Post columnist Earl Ofari Hutchinson suggests the Justice Department could argue that Zimmerman interfered with Trayvon's right to "freedom of movement" on a public street, as the boy was returning to a family home from a 7-Eleven.

The Rev. Al Sharpton has acknowledged the legal hurdles, but wants a civil rights trial to address the question aching the core of many African Americans: "Do Trayvon Martin and the Trayvon Martins of this country have the civil right to go home?"

To prove Zimmerman was racially motivated, others say, look at his description of Trayvon to a police dispatcher when he said "[expletive] punks" and "these [expletives], they always get away." They also cite Zimmerman's pattern of calling police about "suspicious" young black males in the neighborhood as evidence of racial profiling.

Advertisement

These arguments hardly amount to a slam dunk, let alone a layup. For one thing, prosecutors might be at odds to explain how Zimmerman interfered with Trayvon's right to walk the street while he was following the teen ‚ÄĒ that is, from behind. There's also the fact that the street isn't public, but on private property in a gated community.

Zimmerman's pattern of reporting blacks to police "certainly would be a relevant fact," particularly if he spoke in racial terms, William R. Yeomans, a former chief of staff in the Justice Department's Civil Rights Division, says. "But there has to be some proximity to the evidence showing that he was thinking about race when he actually formulates the intent to commit violence."

Prosecutors would have to convince a jury that Zimmerman had racist thoughts not when he profiled Trayvon or called the dispatcher or followed him, but during the fight ‚ÄĒ especially in the moment when he decided to fire his gun.

Advertisement

That requires a witness who overheard Zimmerman use racial epithets or similarly offensive language at the time, or if he bragged later, or a previous pattern of Zimmerman making racist statements.

This kind of evidence helped the Justice Department win 141 convictions on hate crimes in President Obama's first term, up 74 percent from the prior four years. Samuel Bagenstos, who oversaw the cases as Holder's No. 2 official in the Civil Rights Division, says the racial intent found among the defendants wasn't subtle or "unconscious" but "overt."

Meanwhile, Holder has been known to disappoint civil rights leaders. The Justice Department declined to prosecute New York cops acquitted in the 2006 shootings of three men, including 23-year-old Sean Bell, who died in the fracas on the morning of his wedding day. Why no charges? A lack of evidence, the Justice Department said.

Advertisement

Indeed, the problem with Trayvon's shooting is a problem of evidence. Nobody seems to have witnessed the shooting. And the FBI report compiled last year found no evidence of racial bias. The lead police investigator concluded Zimmerman's actions were "overzealous" and reflected a "hero complex," but not racist.

"This looks like a much harder case to prove than the standard run of hate crimes cases the government brings," Bagenstos says.

Any hope for a conviction, such as it was, may have vanished when Zimmerman walked out of the Seminole County courthouse a free man.

Advertisement

Corey Dade, an award-winning journalist based in Washington, D.C., is a former national correspondent at NPR and political reporter at the Wall Street Journal, the Boston Globe and other news organizations. Follow him on Twitter. 

Corey Dade, an award-winning journalist based in Washington, D.C., is a former national correspondent at NPR and political reporter at the Wall Street Journal, the Boston Globe and other news organizations. Follow him on Twitter.