“It’s like we are watching two different trials,” said the Rev. Al Jackson, a pastor in Richmond Heights, a predominantly black community in Miami-Dade County, expressing frustration over the case and how it is unfolding at trial. “The law doesn’t care how this started, but we do. You are punishing this boy for defending himself, even though it wasn’t his fault.”

Even so, race made an entrance on the first day of the trial. John Guy, a prosecutor, said in opening statements that Mr. Zimmerman had “profiled” Mr. Martin and pursued him because he was suspicious of the black teenager who looked as though “he was up to no good,” as Mr. Zimmerman told the police dispatcher in a call that night. He cited Mr. Zimmerman’s apparent frustration in that call, quoting him making derogatory references to potential burglars who always seemed to “get away.”

Race came up again when the jury heard four other phone calls to the police by Mr. Zimmerman reporting suspicious people in the neighborhood, all of them black. The fact that Mr. Zimmerman was studying criminal justice in college and seemed eager for a career in law or law enforcement rounded out the prosecution’s portrait of a would-be vigilante.

Race arose again, in topsy-turvy manner, when Rachel Jeantel, 19, a young black woman who was speaking to Mr. Martin on the phone shortly before he was shot, took the stand. Mr. Martin told her during that call, Ms. Jeantel said, that Mr. Zimmerman was following him; he called him a “creepy-ass cracker.” The defense team quickly jumped on the words, suggesting to the jury that Mr. Martin had profiled Mr. Zimmerman.

In the cocoon of the courthouse, even Mr. Martin’s bullet-scarred hooded sweatshirt, positioned for jurors in a clear plastic frame, appeared less a poignant symbol for the thousands who marched in his name than a lamentable but necessary piece of evidence.

Still, black pastors, sociologists and community leaders said in interviews that they feared that Mr. Martin’s death would be a story of justice denied, an all-too common insult that to them places Trayvon Martin’s name next to those of Rodney King, Amadou Diallo and other black men who were abused, beaten or killed by police officers.

“Profiling, stereotyping, the disparity in treatment of African-Americans when it comes to criminal matters, how imbalanced it all is in the eyes of African-Americans,” said the Rev. Lowman Oliver, the pastor at St. Paul Missionary Baptist Church in Sanford. “That’s why so many eyes are on this case. It’s nationwide and international.”