Discuss as:

Witness: Zimmerman 'never ... tried to help' Trayvon Martin

As thousands protested how Trayvon Martin's shooting was handled, witnesses of the boy's death say they believe the shooter is guilty. NBC's Ron Allen reports.

A woman who says she and her roommate witnessed the final moments of Trayvon Martin's life told Dateline NBC that George Zimmerman had "his hands pressed on his back" and "never turned him over or tried to help him."

Zimmerman's lawyer, when shown part of the interview being aired Sunday night on Dateline, emphasized that his client would be claiming self-defense.

"I think there were efforts made to render aid to Trayvon," Craig Sonner told NBC's TODAY show.

Mary Cutcher told Dateline that she and her roommate both saw Zimmerman "straddling the body, basically a foot on both sides of Trayvon's body, and his hands pressed on his back."

Cutcher added that Zimmerman told her and her roommate to call the police.

"Zimmerman never turned him over or tried to help him or CPR or anything," Cutcher said.

Sonner also reiterated what he had said in recent days, that Zimmerman suffered a broken nose and a gash to the back of his head.

A lawyer for George Zimmerman, who shot 17-year-old Trayvon Martin, believes further investigation will exonerate his client. NBC's Lester Holt has more.

Ben Crump, a Martin family attorney, told NBC News that Sonner was "blaming the victim."

 "Its real simple, if George Zimmerman had done what a neighborhood watchman is supposed to do -- watch -- Trayvon Martin would be alive today," he added.

"Trayvon Martin does not have to identify himself to a stranger," he noted. "George Zimmerman never identified who he was to Trayvon." "If he (Zimmerman) doesn't get out of the car ... if he doesn't act as if he's the police, none of this happens."

A friend of Zimmerman's who appeared on TODAY with Sonner added that Zimmerman, 28, was distraught over the teen's death.

"Right after the shooting he couldn't stop crying," said Joe Oliver, who is African American and a former TV reporter and anchor in Orlando.

PhotoBlog: 'Hoody protests' extend to churches

Zimmerman has not been charged in the Feb. 26 shooting that has ignited racial tensions and raised questions about the Sanford police's handling of the case. Martin was black, and Zimmerman's father is white and his mother is Hispanic.

In a separate interview Sunday, Oliver said that "I'm a black male and all that I know is that George has never given me any reason whatsoever to believe he has anything against people of color.''

On Saturday, Sonner said he believes evidence will show that Florida's "Stand Your Ground" law was properly applied.

"Is George a racist? The answer is no, absolutely not. He's not a racist," Sonner said about his client. "The incident that transpired is not racially motivated or a hate crime in any way. It was self-defense."

Sonner said he's spoken with several of Zimmerman's friends, including some who are African American. "They only have good things to say about him," Sonner said.

In light of the Trayvon Martin incident, a Meet the Press roundtable breaks down violence by citizens against blacks in America.

They're reluctant to come forward, though, because they fear that the backlash over the investigation will make them and their families targets, too, Sonner said.

More from Dateline NBC

Sonner declined to detail what transpired between Zimmerman and the 17-year-old Martin, who was unarmed, but he said he believes the case falls under Florida's stand-your-ground law, which dictates that a person has the right to stand his or her ground and "meet force with force" if attacked.

"I believe what the evidence will show is that this case does fall under that," Sonner said. "I believe we have a good case."

If charges are brought against his client, Zimmerman would be willing to turn himself in to police, Sonner said. "We will follow the law," Sonner said.

Sonner would not say where Zimmerman was. 

White House adviser David Plouffe discusses President Obama's conversations on the Trayvon Martin case.

Amid the outcry over the lack of charges against Zimmerman, the Sanford police chief and state's attorney in the case have both stepped aside.

The U.S. Justice Department has opened a civil rights probe into the shooting, and a grand jury is scheduled to meet April 10 to consider evidence in the case.

Daryl Parks, another Martin family attorney, said federal officials and local officials met with the teen's family Thursday and gave them "a strong sense that (the Department of) Justice was very committed" to investigating the case.

Indeed, President Barack Obama weighed in Friday, calling the shooting a tragedy and saying, "When I think about this boy, I think about my own kids."

But Parks added "it was clear from Justice's statements that charges of a hate crime are going to be a challenge."

Parks also said the Florida Department of Law Enforcement has told the family's legal team that they know Zimmerman's whereabouts, but that it was not clear whether they are offering protection to Zimmerman, who has been in hiding and has received death threats in recent weeks.

Martin's parents also met Friday with the newly-appointed special prosecutor in the case, and the family's legal team plans to pursue a civil case against the Twin Lakes homeowner's association, Parks said.

About 400 people rallied Saturday in downtown Chicago to protest Martin's killing. In a racially divided city beset by shootings, gang violence and run-ins with police, the teen's death brought to mind the 1955 slaying of Emmitt Till, a 14-year-old black boy from Chicago who was shot and bludgeoned to death while visiting Mississippi for supposedly whistling at a white woman. His body was found in the Tallahatchie River.

No one was ever convicted, but Till's killing galvanized the civil rights movement.

"It's a precedent that with the right excuse it's OK to gun down black males," protester Ashten Fizer said of Martin's killing. "It's a return of Jim Crow."

In Washington, D.C., a large crowd gathered in Freedom Plaza to call for justice in the shooting.

Among the demonstrators Saturday was Jimmy Neal, a District of Columbia resident who said his daughter has been asking him questions he didn't want to answer.

Jonathan Ernst / Reuters

People gather at a "Stand Up for Trayvon Martin" rally in Washington, D.C., on Saturday.

"She's asked me the question ... 'Why, daddy, when he was carrying candy and a soda or iced tea and why did the man kill him?' I had to explain that to her. And those are discussions you don't plan to have with your kids," Neal said.

"Hoodie Marches" were organized Saturday in two South Carolina cities over social media. Many of the people participating carried bags of Skittles and wore hooded sweat shirts, like the one Martin wore when he was killed.

Martin was holding a bag of the candy while walking to his father's fiancée's home from a convenience store when Zimmerman started following him, telling police dispatchers he looked suspicious. At some point, the two got into a fight in the gated community and Zimmerman pulled out his gun.

Zimmerman dropped out of public view shortly after the shooting and his whereabouts were unknown. The New Black Panther Party, an African American organization taking its name from the radical group of the 1960s, has placed a $10,000 bounty on Zimmerman.

"All these people who are threatening George, what makes them any better than the person they think he is?'' Oliver said. "You've got all these people wanting to lynch the man and they don't know the whole story.''

NBC's Ron Allen as well as The Associated Press and Reuters contributed to this report.

More content from msnbc.com and NBC News:

Follow US News on msnbc.com on Twitter and Facebook