Growing outrage over Zimmerman’s self-defense claim

>>> good evening. they are driven by a social media came pain, by mainstream media coverage, by sadness and out rablg at the thought that an innocent teenager was killed outside his father's home in florida . to show you the level of concern over this case in florida , this is a rally under way tonight here in new york. national attention has now come crashing down on the case of trayvon martin. he was 17 years old. he was encountered by a neighborhood watch volunteer who had a gun. he has not been arrested, and now that the feds and the media have swoops in on this case, the pressure is on. we begin tonight with ron allen in florida .

>> reporter: with a grand jury about to review the case, today, state investigators gathderred potential evidence at the gated community where 17-year-old trayvon martin was gunned down 21 days ago by neighborhood watchman. today, the police chief said his claim was supported by physical evidence and testimony. the orlando sentinel spoke to a winlz.

>> i saw someone lying on the ground and i heard someone yelling for help. i heard the shot and right when i heard the shot, the screaming stopped.

>> george zimmerman has not been charged in the shooting. neighbors said today they asked him to move out of his townhouse, and residents listed a long grievance of police treatment of young black men before the martin case .

>> they put these black boys in jail and give the all kinds of bogus charges, and they're not true.

>> enough is enough. we're sick and tired of it.

>> reporter: the remarks will go to justice department investigators in washington, and at nat same meeting, sanford's mayor pledged to take action.

>> i want everyone to know i take this personally. i can't right the ship in one day. i know there's a lot of tension.

>> we as people of color are going to stand our ground.

>> at a town hall meeting last night, residents expressed outrage about the stand your ground law that police say justified the shooting. the 2005 law says deadly force is justified if someone believes that such force is necessary to prevent imminent death or great bodily harm. an author of the law said it should not apply in this case.

>> there is nothing in this statute that authorizes someone to pursue and confront other people.

>> all of that gives little comfort to martin's parents who continue their public plea for justice. this morning on "today."

>> i just hurt and my heart hurts because this guy has not been arrested. they decided on the scene to be the judge and jury. and i just want this guy arrested and so he can be brought to justice.

>> reporter: also tonight here, police are saying for the first time that they believe that zimmerman did not confront and pursue martin. that zimmerman had returned to his car and was waiting for police and that martin, the teenager, attacked him. that's why they're sticking to their conclusion that zimmerman acted in self defense . brian?

>> ron allen starting us ought in sanford, florida . there's a