(CBS News) ORLANDO, Florida - We're continuing to examine the evidence in the case of George Zimmerman, the neighborhood watch volunteer charged with murdering an unarmed teenager, Trayvon Martin. Zimmerman claims he acted in self-defense CBS News correspondent Mark Strassmann reports on what the evidence shows -- and what it doesn't show.
The convenience store surveillance video showing Trayvon Martin buying snacks was first seen by his family Thursday night.
"What was it like for Trayvon's mother to see him in that video?" Strassman asked attorney Benjamin Crump, who represents the teenager's parents.
"She said she stayed up most of the night crying last night," he responded. He added: "If you are a parent, you know that is an just unimaginable thought, that this is the last few minutes of my child's life."
The state's evidence file details injuries from the fight, but offers no clear clues to explain who started the confrontation that began as Martin was talking to his girlfriend on his cell phone. Here's what she told police:
Police: And what do you hear Trayvon saying?
Girl: "Why are you following me for?"
Police: And you heard this other voice say what?
Girl: "What are you doing around here?"
One witness told police he saw Martin pummeling Zimmerman like a mixed martial arts expert: "The one guy on top in the black hoodie was pretty much just throwing down blows on the guy, kinda MMA style."
But another witness description is murkier: "Saw a fist fight, just fist, I don't know who was hitting who, and I went back to turn off the stove, and by the time I walked by I heard a shot."
Some of the case's most important evidence has yet to be made public, including Zimmerman's three interviews with police, and his cell phone records. CBS News learned that includes texts Zimmerman sent after the shooting. Some of them disparage leaders of "Justice for Trayvon" rallies with language described as offensive.
Mark O'Mara, Zimmerman's lawyer, has yet to get copies of all those texts.
"So you still will be looking for them?" Strassman asked O'Mara.
"And if that is there?"
"We'll deal with it," said O'Mara. "I don't know the context of it. I don't know what is was in response to. I am sure that as every other part of this case, there will be explanations on both sides. Let's wait and see what we have."
O'Mara expects to get the rest of the prosecution's case in pieces over the next few weeks. Some of the evidence now under seal may be made public only in court.