The attorney for George Zimmerman, the man who shot and killed 17-year-old Trayvon Martin last month, said Monday that Martin initiated the confrontation, beating his client so badly he suffered a broken nose and injuries to the back of his head.

Physical evidence, including a grass stain on the back of his shirt, showed there was a scuffle, lawyer Craig Sonner told ABC News. “When the evidence comes out, it will show that George Zimmerman was acting in self-defense in this case,” Sonner said. “It’s not a racial issue.”

Martin’s parents and their attorney, preparing to fly to Washington for a congressional briefing Tuesday, disputed the account, which contradicted their long-standing assertions that Zimmerman had attacked their son without provocation. Martin was unarmed when he encountered Zimmerman while walking from a convenience store in Sanford, Fla., on Feb. 26.

“There is absolutely no evidence of anything like that except Zimmerman’s word,” Benjamin Crump, the attorney for Martin’s parents, said in an interview. “Trayvon isn’t here to give you his version because Zimmerman shot and killed him.”

Sonner’s account of Zimmerman’s injuries is consistent with the Sanford Police Department report, written by the officer at the crime scene who handcuffed Zimmerman. “I could observe his back appeared to be wet and was covered in grass, as if he had been laying on his back on the ground,” the officer wrote. “Zimmerman was also bleeding from the nose and back of his head.”

George Zimmerman is the man who shot and killed 17-year-old Trayvon Martin last month. Zimmerman’s lawyer said Monday that Martin initiated the confrontation, beating his client so badly he suffered a broken nose and injuries to the back of his head. (HANDOUT/REUTERS)

When Zimmerman was placed in the back of the squad car and given first aid, the officer heard him say, “I was yelling for someone to help me, but no one would help me,” according to the police report.

On at least one of the eight taped 911 calls made to police, screams can be heard in the background. Martin’s parents believe it is their son screaming for help. But a friend of Zimmerman’s said on television Monday he believed it was Zimmerman’s voice in the background.

A federal law enforcement official involved in the investigation said that Zimmerman told authorities he was returning to his sport-utility vehicle after calling police when Martin confronted him.

The official, who spoke on condition of anonymity because the investigation is in its early stages, said that Zimmerman recounted Martin challenging him by saying, “You got a problem with me?”

“Zimmerman said no,” the official said, citing Zimmerman’s account. “Martin said, ‘Now you do,’ and then punched him in the nose.” The exchange was first reported by the Orlando Sentinel, which also said Zimmerman had told police that Martin got on top of Zimmerman and began slamming his head into the sidewalk.

New information was also revealed Monday about the circumstances of Martin’s visit with his father in Sanford. Crump said that Martin was staying with his father’s fiancee, because he had been recently suspended for 10 days from his high school in Miami after an empty baggie that once held marijuana and still had some residue was found in Trayvon’s book bag.

“They found he and his friends with a baggie,” Crump said.“They wouldn’t tell whose bag it was,” Crump said. “So Trayvon and a friend were suspended.”

Crump said the suspension was “completely irrelevant” to the shooting. “It has no bearing whatsoever,” he said.

Sybrina Fulton, Martin’s mother, said the story about his suspension was leaked by the police to smear her son’s reputation.

Sanford City Manager Norton N. Bonaparte Jr. said that the information in the Orlando Sentinel had not been provided to the media through an authorized police source and was possibly a leak in the department. But, he said, the account in the newspaper was “consistent with the information provided to the State Attorney’s Office by the police department.”

Martin’s shooting has sparked a national outcry over racial profiling, with the family’s supporters demanding that police arrest Zimmerman, who has not commented publicly on the case and who remains in hiding.

Fulton and her ex-husband, Tracy Martin, Trayvon’s father, will attend a congressional briefing Tuesday afternoon on racial profiling and state “stand your ground” laws with several Democratic representatives, including Sheila Jackson Lee (Tex.), John Conyers (Mich.) and Corrine Brown (Fla.).

Twenty-one such laws have been passed in the United States in recent years. Sanford authorities cited Florida’s “stand your ground” law as the reason Zimmerman has not been arrested.

“When the Sanford Police Department arrived at the scene of the incident, Mr. Zimmerman provided a statement claiming

he acted in self-defense, which

at the time was supported by physical evidence and testimony,” Bonaparte said in a statement last week.

“By Florida Statute, law enforcement was PROHIBITED from making an arrest based on the facts and circumstances they had at the time,” Bonaparte wrote in the statement, citing statutes including Florida’s “stand your ground” law.

The Florida law, which was the first such measure passed in the country, was signed in 2005. It was backed by the National Rifle Association and opposed by police officials, who feared it would encourage untrained vigilantes to take the law into their own hands.

John F. Timoney, a former Miami police chief and former head of the Police Executive Research Forum, said he and other Florida police chiefs wrote to the Florida legislature in 2005 opposing the “stand your ground” concept.

“Laws like ‘stand your ground’ give citizens unfettered power and discretion with no accountability,” Timoney wrote in an opinion piece in the New York Times last weekend. “It is a recipe for disaster.”

In Florida, the “stand your ground” law specifically gives citizens the right to use force — even deadly force — in a public space if they feel threatened. Under the Florida statute, a person “who is attacked in any other place where he or she has a right to be has no duty to retreat and the right to stand his or her ground and meet force with force.”

While most of the laws were passed by Republican-controlled states, such as Pennsylvania, not all were. Oklahoma’s Democratic governor signed a “stand your ground” law. President Obama’s Homeland Security secretary, Janet Napolitano, signed such a law when she was the Democratic governor of Arizona.

Sen. Charles E. Schumer (D-N.Y.) wrote Attorney General Eric H. Holder Jr. on Monday, asking the Justice Department to investigate the laws.

“These laws seem to be encouraging vigilantism by allowing individuals to use deadly force as a first resort,” Schumer wrote.

Staff researcher Julie Tate contributed to this report.