Lawyers representing George Zimmerman, the man who shot unarmed Florida teenager Trayvon Martin, say they are dropping him - as a new announcement on the case is imminent.

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The latest twist in the Martin case came at a hastily called press conference in Sanford, Florida, where Craig Sonner and Hal Uhrig revealed they had not been in contact with their erstwhile client for days, and had no idea where he was.

"I know his phone works", Sonner said, "He won't return my phone calls. He won't return my texts. He won't even give me a collect call." And they said Zimmerman had been taking actions in relation to the case without their knowledge, contacting the state special prosecutor's office on Tuesday, and speaking to Sean Hannity of Fox News, without seeking their advice first.

Zimmerman had also set up his own website, asking for donations to help with his living expenses and legal defence, again without consulting his legal team. On the site, he says he has been forced to give up his job, his family and his home: now his former legal team has expressed concerns about his health, describing his mental state as shaky.

The special prosecutor in charge of the case, Angela Corey, announced late on Tuesday that she would hold a press conference within the next 72 hours, possibly in Sanford itself, where the shooting happened. Ms Corey threw the case into limbo after announcing that she wouldn't be calling a grand jury to decide whether Zimmerman should face prosecution, but would decide the issue herself.

As for Trayvon Martin's family, their lawyer Benjamin Crump said he was worried that Zimmerman might try to flee justice: the situation could have been avoided, he said, if the police had "just simply arrested him" in the first place.

You plan for the worst, and hope for the best. Jeff Triplett, mayor of Sanford

The continued uncertaintly is hardly likely to ease the simmering tensions in Sanford itself. A police car was shot at late on Monday night in the predominantly black neighbourhood of Goldsboro. According to ABC news, the authorities have put emergency operation centres on high alert. They quote the local mayor, Jeff Triplett as saying: "Are we a kindling box? Sure... you plan for the worst, and hope for the best."

An online petition endorsed by Trayvon Martin's family has gathered more than 2.2m signatures calling for Zimmerman to be prosecuted. But elsewhere there have been distressing racial slurs: one linked to Trayvon's name on an electronic road sign that was deliberately altered in Detroit, another in graffiti sprayed onto a black cultural centre in Ohio State University.

Inevitably, links have been drawn to another shooting rampage in Tulsa, Oklahoma, when three black men were killed and two badly injured earlier this month. The two white suspects charged with the murders have confessed: one had posted a racist message on Facebook about the shooting death of his own father, which he blamed on a black man. Police have not said whether the killings were racially motivated, but it's all adding to the uncomfortable questions about race.

Gun culture questioned, too

Both cases, too, have raised another taboo: America's gun culture - and specifically, 'Stand Your Ground' laws like the one in Florida that meant George Zinmerman was neither questioned nor arrested after claiming he shot Trayvon Martin in self defence. Several major corporations, including Kraft and Coca Cola, announced plans last week to pull out of a conservative lobby group that has strongly supported the controversial law.

Now activists are piling pressure on other firms, like Walmart and AT&T to cut their ties with the American Legislative Exchange Council, which was set up to push for ready-made bills on issues ranging from tax policy to criminal justice. As part of that, they had been pushing for other states to adopt laws similar to the one in Florida, allowing people to use lethal force if they felt threatened, without facing prosecution.

Coca Cola has insisted its decision to suspend its involvement with ALEC was solely based on "efforts to oppose discriminatory food and beverage taxes, not on issues that have no direct bearing on our business." However, opponents of the gun law have already begun targeting the telecoms firm AT&T, flooding their headquarters with phone calls demanding that they stop funding the lobby group.

Carl Dinnen reports from Washington:

One company whose involvement in ALEC remains unclear is Mars. They have yet to reply to repeated requests from C4 News on their links to ALEC. I've been told they did exhibit at ALEC's conference last year. Mars do have a very clear, albeit unwitting, link to the Trayvon Martin affair; it was a bag of their Skittles he was holding when he was shot. Skittles have since become an unofficial symbol of the Justice for Trayvon campaign.  

ALEC called Martin's death a "great tragedy", according to CNN, adding that it was unclear whether the "Stand Your Ground" law should even have applied. Spokeswoman Kaitlyn Buss said private members didn't neccessarily agree with all its policy initiatives: "ALEC's members are united by a common interest in free market enterprise, and limited government," she said.

Race, class, and now the right to bear arms - America is already deeply divided over the Trayvon case and its aftermath, by race, by class and by generation. Now the right to bear arms is thrown into the mix: the death of a young man opens another fault-line, over another political taboo.

Felicity Spector writes about US politics for Channel 4 News

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