Opening statements begin Zimmerman trial Lawyers quote expletives, tell a joke in opening trial statements in the killing of Trayvon Martin Martin's father seen crying; defendant George Zimmerman shows no emotion 62% in a CNN poll say the charges against Zimmerman are "probably" or "definitely" true Editor's note: This story contains language that may offend some readers. (CNN) -- A prosecuting attorney greeted the jury in the George Zimmerman trial Monday with a quote full of expletives, while his adversary decided it was appropriate to tell jurors a knock-knock joke. And that was just the beginning of opening statements in Zimmerman's long-anticipated murder trial. In a case that has ignited national debate about gun laws and race relations, Zimmerman, a neighborhood watch captain, is accused of second-degree murder in the fatal shooting of 17-year-old Trayvon Martin in February 2012 in Sanford, Florida. Prosecutor John Guy's first words to the six-woman jury may have raised a few eyebrows. Good morning. 'F*****g punks, these a******s all get away,'" Guy quoted Zimmerman. These were the words in this grown man's mouth as he followed this boy that he didn't know. Those were his words, not mine. Zimmerman, Guy said, "got out of his car with a pistol and two flashlights to follow Trayvon Benjamin Martin, who was walking home from a 7-Eleven, armed" with a fruit drink and a bag of candy. Eventually the two became entangled on the ground in a fight. A witness has said Martin was on top of Zimmerman, Guy said. "The defendant claims that while Trayvon Martin was on top of him, he said, 'you are going to die tonight,'" said Guy. Nobody heard that. Guy told jurors that no witnesses saw what happened the night of the shooting from beginning to end. Witnesses only saw "slices" of what happened, he said. "We are confident that at the end of this trial you will know in your head, in your heart, in your stomach that George Zimmerman did not shoot Trayvon Martin because he had to," Guy said. He shot him for the worst of all reasons, because he wanted to. The Martin family sat watching the proceedings behind State Attorney Angela Corey. Zimmerman's parents were seated behind the defendant in the second row. The pews in the public gallery were filled to capacity. At one point, Martin's father began crying as Guy detailed how officers tried to save his son's life. Zimmerman has mostly stared straight ahead without any signs of emotion. Following Guy's statement, defense attorney Don West came forward to woo the jury. As he began, he told a knock-knock joke. But it failed to win a laugh. Knock knock. Who's there? George Zimmerman. George Zimmerman who? Good, you're on the jury," he said. West quickly got on with the business of making his case: that Zimmerman was forced to act in self-defense to save his own life. The evidence will show this is a sad case; no monsters here. ... George Zimmerman is not guilty of murder. He shot Trayvon Martin after he was viciously attacked. With the help of PowerPoint visuals, West spent hours hammering away at his argument. He broke down Zimmerman's non-emergency 911 call in which he first reported seeing Martin and told about following him. "Little did George Zimmerman know at the time in less than 10 minutes from him first seeing Travyon Martin that he, George Zimmerman, would be suckered punched in the face, have his head pounded on concrete and wind up shooting and tragically killing Trayvon Martin," West told jurors. West also deconstructed a 911 call a neighbor made, in which it is possible to hear screams and a shot in the background that West said was the sound of the fatal bullet. As the dramatic recording audio filled the courtroom, Zimmerman showed no emotion. Martin's mother left the courtroom. West quoted a witness named John Good who described the fight. "He called it a 'ground and pound' by Martin, who he said was on top of Zimmerman, beating him "senseless." "He saw enough that this was serious," West said. Zimmerman cried out for help, looked at Good and said, "help me." But the beating continued while Good went inside his home to call 911, West said. There was a shot. Shortly afterward, according to West, Zimmerman said Martin "was beating me up, and I shot him." West showed jurors photos taken of Zimmerman after the fight. "What you can really see in these pictures that you will have in evidence are the lumps," West said. The big knots on each side of his head. Consistent with having his head slammed into concrete. Shortly before court got under way, Martin's mother, Sybrina Fulton, spoke to reporters, asking people to "pray for me and my family because I don't want any other mother to experience what I'm going through now." Judge: No state expert testimony on 911 calls In a CNN poll released Monday morning, 62% of respondents say the charges against Zimmerman are probably or definitely true. Here is a summary of the key figures and elements involved in the trial: Before the shooting, Trayvon Martin was living with his mother and his older brother in Miami Gardens, Florida, where he was a student at Dr. Michael Krop Senior High School. He was there for seven days before his death. After Martin was killed, the medical examiner who conducted his autopsy said the teen had traces of THC, an active ingredient in marijuana, in his system when he died. George Zimmerman, now 29, was a neighborhood watch captain in the gated community where Martin was staying temporarily when he died. In 2003, Zimmerman enrolled at Seminole State College in Florida and earned a vocational certificate as an insurance agent. Before his marriage to Shellie Nicole Dean in 2007, Zimmerman and his then-fiancee filed domestic violence protection orders against each other. A 2005 scuffle involved pushing and punching, police said. In July 2005, Zimmerman was arrested for an assault on an officer and resisting arrest after an incident at a bar. Zimmerman said the case was the result of mistaken identity. In October 2005, Florida passed the "stand your ground" law, allowing its residents to meet "force with force" if they believe they or someone else is in danger of being seriously harmed by an assailant. On August 4, 2011, Zimmerman submitted his first report to the Sanford Police Department about a suspicious black male walking around in the Retreat at Twin Lakes neighborhood, where Zimmerman was a neighborhood watch captain. The next day, Zimmerman called the department again, reporting another suspicious black male lurking in the area. On February 2, 2012, Zimmerman called in a similar report to the department. The 28-year-old called the department's nonemergency line to report "a suspicious person" in the neighborhood. Officials told him not to get out of his car or approach the person. Just before he was killed, Martin was walking back from a nearby convenience store, headed to his father's girlfriend's home. The day after the shooting, Martin's father filed a missing person report because his son had failed to return home. Officers with the Sanford Police Department visited Tracy Martin, who later identified his son's body using a picture. Investigators received a fax from Altamonte Family Medical Practice on March 8 containing the medical records identifying the injuries suffered by Zimmerman the night of the shooting. In mid-March of that year, the FBI received a report that Zimmerman had contacted a gun store about acquiring a new firearm because, according to Zimmerman, his "life is in danger" and he "needs more guns." On March 22, a petition on Change.org -- created by Martin's parents and calling for the arrest of George Zimmerman -- surpassed 1.3 million supporters. During that interview, he said he would not have done anything differently the night of the shooting. In April of 2013, Zimmerman waived his right to a "stand your ground" pretrial immunity hearing. A judge declared that most of the information regarding Martin's and Zimmerman's backgrounds would be barred from the trial, including Martin's school suspension history. CNN legal analyst Sunny Hostin and CNN's Grace Wong contributed to this report.