EATONVILLE, Fla. – Wearing hooded sweat shirts similar to the one Trayvon Martin wore on the night he was killed, many preachers and worshippers echoed calls for justice Sunday in the shooting death of the unarmed black teenager in Florida last month.

Martin was shot a month ago today while wearing a “hoodie” as he walked home on a rainy night in a gated community. The neighborhood watch volunteer who shot him, George Zimmerman, 28, called police to report the hooded figure as suspicious; Martin, 17, was carrying a bag of Skittles and a can of iced tea, and talking to his girlfriend on his cellphone.

In religious centers from Florida to Atlanta, New York and Chicago, messages from pulpits couldn’t help but touch on a seemingly avoidable tragedy. But while the call continued to be for the arrest of Zimmerman, there were also pleas to use the incident to spark a larger movement.

“How do we turn pain into power?” the Rev. Jesse Jackson asked a standing-room-only congregation of hundreds while preaching at Macedonia Missionary Baptist Church in Eatonville, Fla., about 20 miles from the site of the Sanford, Fla., shooting. “How do we go from a moment to a movement that curries favor?”

Meanwhile, legal experts say the U.S. Justice Department could bring a hate crime charge against Zimmerman if there is sufficient evidence the slaying was motivated by racial bias and not simply a fight that spiraled out of control.

So far, only one such clue has surfaced publicly against Zimmerman. On one of his 911 calls to police that night, Zimmerman muttered something under his breath that some listeners say sounds like a racial slur. Zimmerman’s father is white, and his mother is Hispanic.

“It sounds pretty obvious to me,” said Donald Tibbs, a Drexel University law professor who has closely studied race, civil rights and criminal procedure. “If that was a racial epithet that preceded the attack on Trayvon Martin, we definitely have a hate crime.”

Others, however, say the recording is not clear enough to determine what Zimmerman actually said. And many experts say more evidence would be needed that he harbored racial prejudice against black people and went after Martin for that reason alone. There had previously been burglaries in the complex committed by young black males, possibly heightening Zimmerman’s suspicions.