Editor's note: This story contains language that may offend some readers. Watch Anderson Cooper's special 'Self Defense or Murder? The George Zimmerman Trial' tonight 10pm ET.
(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."
In the first day of testimony, jurors heard witnesses recount Martin's trip to the convenience store, Zimmerman's call complaining about a suspicious person walking through his neighborhood before Martin's killing, and a call from the previous August, in which Zimmerman reported an alleged burglary to police.
Proceedings ended for the day when defense attorney Mark O'Mara objected to the earlier call, which prosecutors argued was necessary to explain Zimmerman's remark about burglars who "get away."
The Martin family sat watching the proceedings behind State Attorney Angela Corey. Before witness testimony began, Judge Debra Nelson denied a defense request that Martin's father, Tracy Martin, leave the courtroom.
Tracy Martin is a potential witness, and potential witnesses can be forced to sit outside of the courtroom to keep their testimony from being tainted by other witnesses. But the next-of-kin of victims are allowed to remain in court even if they're expected to testify.
O'Mara also accused Tracy Martin of using an obscenity toward a friend of Zimmerman's while holding the door for him during a hearing two weeks ago. The friend, Timothy Tucholski, testified that he hadn't wanted to make an issue of it before.
"I wasn't planning on coming up here. I don't want to be sitting here," he said.
But Nelson denied the request, and Martin remained in court -- but Zimmerman's parents were covered by the rule regarding potential witnesses and had to sit outside, as did Benjamin Crump, the lawyer for Martin's parents.
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. Later, West apologized. "No more bad jokes, I promise that," he told jurors. "I was convinced it was the delivery."
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 home his argument.
He broke down Zimmerman's 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.
"At the moment this actually became physical was that Trayvon Martin -- I will use my words -- that Trayvon Martin decided to confront George Zimmerman," West said. "That instead of going home. He had plenty of time. This is, what, 60 or 70 yards. Plenty of time. He could've gone back and forth four or five times."
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."
"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 also disputed the prosecution's claim that Martin was unarmed.
"Travyon Martin armed himself with the concrete sidewalk and used it to smash George Zimmerman's head," said West. "No different than if he picked up a brick or smashed his head against a wall. That is a deadly weapon."
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."
Among the first prosecution witnessed called was the 911 dispatcher who took Zimmerman's call before the shooting. Seat Noffke testified that he was trained to give general commands instead of direct orders to people.
When Zimmerman said he was following Martin, Noffke told him, "Okay we don't need you to do that." Noffke told the prosecutor he's liable for any direct orders he gives someone.
On cross-examination, defense attorney O'Mara pointed out that Noffke asked Zimmerman, "Which way is he running?"
"If you tell somebody twice to let you know if the person that they're concerned about is doing anything else -- do you think they're going to keep their eye on them?" asked O'Mara.
"I can't answer that," said Noffke.
"You did tell him twice to let you know if that guy did anything else," said O'Mara.
"Yes sir," said Noffke.
Noffke went on to say he only wanted a location of the suspect for officers and that he never told Zimmerman to follow or keep his eye on Martin.
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."
Martin was black, and Zimmerman identifies himself as Hispanic.
In a CNN poll released Monday morning, 62% of respondents say the charges against Zimmerman are probably or definitely true.
CNN legal analyst Sunny Hostin and CNN's Grace Wong contributed to this report.