(Editor's note: This story contains language in the 4th paragraph that some readers may find offensive)
By Tom Brown and Barbara Liston
SANFORD, Florida (Reuters) - Neighborhood watchman George Zimmerman killed Trayvon Martin simply because "he wanted to," because he was an armed vigilante, and because he viewed the 17-year-old whom he'd never met as just another "punk," a prosecutor said in opening statements to the jury in a trial that promises to raise thorny issues of race and gun rights.
In a case that centers on a shooting that occurred without a clear eyewitness on a rainy, dark night more than a year ago, prosecutor John Guy sought to cut through doubts surrounding the incident in a fiery 30-minute opening statement that branded Zimmerman as the aggressor for the six jurors who will decide the case.
As the second-degree murder trial opened in earnest after two weeks of jury selection and evidentiary rulings, the prosecutor began by bluntly quoting from Zimmerman's call to a police dispatcher after first spotting the unarmed, black teen.
"'Fucking punks. These assholes, they always get away'," Guy repeated, going on to say those were the "hate-filled words he used to describe a total stranger."
Zimmerman's defense attorney Don West opened with his own unusual gambit, opting to tell a "knock-knock" joke, which fell flat in the courtroom. "Knock knock. Who's there? George Zimmerman. George Zimmerman who? Good, you're on the jury," he said.
West went on to offer a wholly different view of his client - who is out on bail and appeared in court wearing a charcoal gray suit - and the events of February 26, 2012 in a gated community in Sanford, Florida.
Zimmerman was "viciously attacked" by Martin and acted in self-defense, attorney Don West said.
In his 2-1/2 hour statement to the jury, the defense attorney said a witness, who he identified as a homeowner near the site of the altercation, would testify about a man clad in the color of the clothing Martin was wearing "mounting" a man on the ground in mixed martial arts fashion and "basically beating him senseless."
West said contrary to what has often been said about the case, Martin was not unarmed. "Trayvon Martin armed himself with the concrete sidewalk and used it to smash George Zimmerman's head ... That is a deadly weapon," he said.
Zimmerman showed no emotion as he stared straight ahead and away from the prosecutor.
The parents of both Zimmerman and Martin were seated on different sides of the courtroom at the start of the day, but Zimmerman's parents were quickly instructed to leave after the prosecution said they might be called as witnesses.
Martin's mother, Sybrina Fulton, later left the courtroom when West played the jury a tape of a 911 call in which screams can be heard before the fatal shot. "To sit there and hear her child's final moments was very tough," said Daryl Parks, a lawyer for the Martin family.
Both families say the screams on the tape came from their son, but the FBI has been unable to say conclusively whose voice it is.
Zimmerman, 29 and part Hispanic, was the neighborhood watch captain in the Retreat at Twin Lakes community in Sanford at the time of the killing. He has pleaded not guilty to the charge of second-degree murder and could face life imprisonment if convicted.
Martin was a student at a Miami-area high school and a guest of one of the homeowners. He was walking back to the residence after buying snacks at a nearby convenience store when he was shot in the chest during a confrontation with Zimmerman.
Much of what happened during the fatal encounter is still a mystery. Neighbors who provided differing versions of what they glimpsed of the altercation are expected to testify during the trial. Also to testify is a girl who was on the phone with Martin moments before his death and says she heard the events unfold until the line went dead.
Guy portrayed Zimmerman as a man with a concealed weapon who committed a vigilante-style killing, not a dutiful watch guard on alert for signs of suspicious activity after a string of robberies in his neighborhood.
"George Zimmerman did not shoot Trayvon Martin because he had too. He shot him for the worst of all reasons, because he wanted to," said Guy, the prosecutor.
Guy also told the jury there was "irrefutable physical evidence" that showed Zimmerman was lying when he told police that Martin attacked him. No blood or DNA from Zimmerman was found on Martin's hands or elsewhere on his body or clothing, he said. That is despite Zimmerman's claims that Martin punched him to the ground and covered his bleeding, broken nose with his bare hands as he pounded his head into the ground.
Six jurors, all women, were selected last week to hear the racially charged murder case against Zimmerman. They will be sequestered for the duration of the trial, which is expected to last two to four weeks.
The case triggered civil rights protests and debates about alleged treatment of blacks as second-class citizens under the U.S. justice system, since police did not arrest Zimmerman for 44 days.
However, there is a high bar for the prosecution to prove second degree murder which requires them to show that Zimmerman acted with "ill will, hatred, spite or an evil intent," and showed "an indifference to human life," according to Florida jury instructions.
Under Florida's Stand Your Ground law, which was approved in 2005 and has since been copied by about 30 other states, people fearing for their lives can use deadly force without having to retreat from a confrontation, even when it is possible.
Additional reporting and writing by David Adams and Paul Thomasch. Editing by Peter Henderson and Grant McCool