SANFORD, Florida (Reuters) - A neighborhood watch captain told police he fatally shot Treyvon Martin after the teenager punched him, knocked him down and slammed his head into the ground, the Orlando Sentinel reported on Monday.
At least one witness told police he saw Martin, 17, atop George Zimmerman, 28, and that Zimmerman was calling for help, the newspaper said, adding that other witnesses disputed who the cries were coming from.
ABC News quoted a police source as saying that Zimmerman, in a written statement, claimed that Martin tried to take his gun.
The February 26 killing of the black teenager as he walked through a gated community by Zimmerman, a white Hispanic, has triggered protests around the country and calls for Zimmerman's arrest.
Zimmerman had followed Martin and reported him to police before their deadly encounter. He said believed the young man in a "hoodie" hooded sweatshirt looked to be "up to no good."
Zimmerman's attorney has said he acted in self-defense. He has not been arrested and Florida's "Stand Your Ground" law, which broadened the legal definition of self-defense when it was passed in 2005, provides people with immunity from detention or arrest if they use deadly force in their own defense without clear evidence of malice.
Sanford police said they could neither confirm nor deny the Sentinel story about Zimmerman's account of the incident, which occurred as Martin returned from a convenience store carrying candy and a can of iced tea.
Florida law enforcement has been under fire for weeks as protests decrying inaction in the case have spread to cities across the country. Florida Governor Rick Scott on Monday cautioned against a rush to judgment and state authorities were still gathering facts.
"Justice will prevail," Scott said in an interview with Reuters Insider in New York. "That's what we all want. We want the ... facts and we want to know that justice happens."
Protesters, many dressed in hoodies like the kind Martin wore at the time of his death, point to a 911 call Zimmerman made before the altercation began.
Last Thursday, Scott said State Attorney Norman Wolfinger had agreed to remove himself from the investigation. Scott appointed another Florida prosecutor, Angela Corey, to handle the case. He also created a task force to study crime prevention and specifically the state's Stand Your Ground law.
Asked if the case rose to the level of a possible hate crime, Scott said such a judgment would be premature.
Corey called for patience on Monday as her team of investigators continues looking into Martin's killing.
"Justifiable use of deadly force has been asserted in this case, will continue to be asserted, which will make our job more difficult," Corey told CNN, referring to the Stand Your Ground law.
"However, we do believe when we're done with our investigation the family will know all of the facts and details, as will the public. But they must be patient and we ask for their indulgence."
Martin, a Miami high school student, was in Sanford, staying at the home of a friend of his father, because he had been suspended from school shortly before his death.
On Monday, a family spokesman said the 10-day suspension came after school officials discovered marijuana residue in a plastic bag inside Martin's book bag.
"Regardless of Trayvon's suspension, it had nothing to do with what happened on February 26," Ryan Julison, the family spokesman, told reporters.
Martin's mother, Sybrina Fulton, suggested in comments at a news conference that the marijuana residue report was aimed at smearing her dead child.
"They've killed my son and now they're trying to kill his reputation," she said.
(Additional reporting by Edith Honan and Dan Trotta; Editing by Tom Brown and Bill Trott)