A scandal that began with an act of vigilantism is threatening to breed more of the same, after a weekend of escalating tension saw militant activists announce a $10,000 (£6,300) reward for the "capture" of black teenager Trayvon Martin's killer.
George Zimmerman, a neighbourhood watch volunteer who followed and then shot the unarmed boy, had the bounty publicly placed on his head during a protest in Sanford, the Florida commuter town where Trayvon died.
It was announced by Mikhail Muhammad, leader of a small militant organisation called the New Black Panther Party, who said he was seeking up to 10,000 black men willing to form a militia to find Mr Zimmerman and administer what they regard as justice.
Asked if he was inciting violence, Mr Muhammad said: "An eye for an eye, a tooth for a tooth." To the sound of cheers from followers, who wore black uniforms, he promised: "If the government won't do the job, we'll do it."
His comments were denounced by mainstream civil rights campaigners. Jesse Jackson, who preached at a Baptist church in Sanford yesterday, called it a "diversion," telling reporters: "I think disciplined, persistent, non-violent action works." The incident nonetheless highlights the increasingly polarising nature of the controversy surrounding Trayvon's death.
The 17-year-old, who was shot on 26 February, was remembered during protests in Los Angeles, Washington, Chicago, New York and several other American cities over the weekend.
Demonstrators wore hooded tops and carried bags of Skittles, the brand of confectionery Trayvon was carrying during his fatal journey from a local convenience store to the home of his father's girlfriend, in a community called The Retreat at Twin Lakes.
Supporters of Mr Zimmerman, who claims to have killed Trayvon in self-defence, began publicly lobbying on his behalf. Joe Oliver, a "family friend" who appeared on ABC yesterday, said that he "couldn't stop crying" about the incident and is now in fear of his life.
Mr Oliver, who is mixed-race, was accompanied by Craig Sonner, Mr Zimmerman's attorney. Both men vigorously denied that their friend, who was initially described as a "white male" by police but claims (despite his appearance and surname) to be Hispanic, is racist. Records show that Mr Zimmerman had called emergency services almost 50 times in the past year to report suspicious activity in his neighbourhood. In most recorded instances, he identified the alleged "suspects" as young black males.
Shortly before Trayvon's death, Mr Zimmerman decided to pursue him, against the advice of a 911 operator. On a tape recording of his telephone call to police, he complains, "these assholes, they always get away". Then he appears to utter the slur "f***ing coons".
Mr Oliver was played an enhanced recording of the call by ABC, but claimed that Mr Zimmerman was instead saying "f***ing goons". He insisted that "goon is a term of endearment in the high schools these days". He then alleged that a screaming man, who can be heard in the background of other 911 calls made to Sanford police on 26 February, sounded like Mr Zimmerman. Trayvon's parents have previously identified the distressed man as their son.
Mr Sonner used the ABC interview to claim that photographs of Mr Zimmerman and Trayvon have given a misleading impression of the relative sizes of the two. Trayvon was taller than his killer, he said.
Mr Zimmerman remains in hiding. Local police, who failed to arrest Mr Zimmerman, arrested a man for sending threatening emails to Bill Lee, Sanford's former police chief. Mr Lee decided to step down "temporarily" last week while officials review the case to establish whether Mr Zimmerman should face charges.