(CBS) The second week of testimony in the trial of suspected murderer George Zimmerman is scheduled to launch Monday in a Florida courtroom. Several key witnesses testified during last week's proceedings, one of whom said he believes Trayvon Martin was on top of George Zimmerman moments before the fatal gunshot.
Many people who either heard or saw portions of the Feb. 26, 2012 confrontation or its aftermath, including police, first responders, neighbors and a friend of Trayvon Martin's who was on the phone with the teen just before his death took the stand last week. The jury heard several frantic 911 calls placed the evening of the fatal altercation and saw graphic photos of Martin's body, face down in the grass. They also saw evidence including the package of Skittles Martin had purchased before his death and Zimmerman's gun.
The Martin family attended the proceedings last week, sometimes growing emotional.
Zimmerman, a former neighborhood watch volunteer, is charged with second-degree murder. He claims he shot Martin in self-defense after the teen attacked him and slammed his head into a sidewalk.
Last week's testimony followed opening statements Monday, during which prosecutors launched with the profanity-laced language Zimmerman used as he called non-emergency dispatchers to report a suspicious person in his neighborhood. Prosecutors said Zimmerman profiled Martin as a criminal, followed him, confronted him, and then shot him "because he wanted to."
In a starkly different picture of events, defense attorneys said the former neighborhood watch volunteer was "viciously attacked" and acted in self-defense. In another contrast to the prosecution's dramatic opening statement, defense attorney Don West opened with a "knock knock" joke.
"Knock, knock, who's there? George Zimmerman. George Zimmerman who? All right good, you're on the jury. Nothing? That's funny," said West.
In a blow for prosecutors Friday, neighbor John Good told the court that he believed he saw Martin on top during the altercation and heard George Zimmerman calling for help.
Good testified that he saw a man in dark clothing on top of a man who was wearing red or light-colored clothing with lighter skin. Zimmerman, 29, was wearing a red jacket the night of the altercation, and Martin, 17, was wearing a dark hooded sweatshirt.
Good, however, said he couldn't say for sure Martin was striking Zimmerman.
Another key witness, Martin's friend Rachel Jeantel, said she heard Martin saying "Get off, get off" before the line went dead as she spoke to him on the phone that night.
Jeantel, 19, was a crucial witness for prosecutors, though the defense aimed to highlight inconsistencies in her story in a lengthy cross-examination during which she appeared to grow exasperated. She was sometimes difficult to understand, prompting attorneys and the judge to ask her to speak up and repeat her answers to questions.
Jeantel said Martin told her that a man he described as a "creepy ass cracker" was following him through the community as he was walking home from buying snacks at a 7-Eleven. Later, she said she heard Martin ask, "Why are you following me for?" and a "hard-breathing man" ask, "What are you doing around here?"
That's when Jeantel said she heard a "bump," a sound like "wet grass," and Martin saying, "Get off, get off."