The Miami Herald, Walter Michot) MAGS OUT, Associated Press
Francesca Placide, a student at Michael Krop High School displays her black t-shirt in tribute to Trayvon Martin, Monday, March 26, 2012, in Miami. There have been rallies around the country as anger has spread over the shooting a month ago of Martin, 17, who died after neighborhood watch captain George Zimmerman reported him to police as suspicious and then followed him.

Related Article: Editorial: Getting Trayvon Martin's case right

Trayvon Martin physically assaulted and threatened to kill George Zimmerman before Zimmerman took out a handgun and shot him, Zimmerman's father told an Orlando news station.

The Miami Herald reports that, Robert Zimmerman said his son shot Martin because "Martin got on top of him and just started beating him in the face, in his nose, hitting his head on the concrete.

According the Boston Globe, surveillance video shows George Zimmerman being lead from a police car in handcuffs after the incident, and an attorney for Martin's family says he did not have any injuries to his face or head.

Martin's family has repeatedly asserted that Martin did nothing wrong.

On Feb. 26, Martin left his father's fiance's house to walk to a nearby convenience store. While returning home, neighborhood watch captain George Zimmerman saw Martin and called police to report suspicious behavior.

According to audio of the call, Zimmerman told police that he though Martin was "up to no good" and "on drugs or something." When police arrived, they found Martin face-down with a gunshot wound to the chest.

The incident has sparked a national dialogue on race. Activists wear hoodies, clothing that Martin was wearing the night he was killed, as a sign of solidarity.

Witness accounts of the shooting have varied widely.

Mary Cutcher, who heard the altercation from her kitchen, told CNN "Zimmerman was standing over the body with -- basically straddling the body with his hands on Trayvon's back And it didn't seem to me that he was trying to help him in any way. I didn't hear any struggle prior to the gunshot."

Martin's girlfriend, who was on the phone with Martin seconds before the shooting said that she heard a brief exchange between Martin and Zimmerman.

"What are you stopping me for?" Martin asked Zimmerman, according to the girl.

"What are you doing around here?" Zimmerman said.

According to CNN, "The girl said she then got the impression that an altercation was taking place and that someone had pushed Martin, because the headset fell out of his ear, and the phone shut off."

A witness identified as "John" only corroborated Zimmerman's story to FOX 13 in Tampa Bay.

According to FOX 13 " Sanford police say Zimmerman was bloody in his face and head, and the back of his shirt was wet and had grass stains, indicating a struggle took place before the shooting."