In a powerful and sometimes shocking statement marking the opening of George Zimmerman’s long-awaited murder trial in Florida, a state prosecutor told the jury of six women—five white, one Hispanic—that the defendant profiled 17-year-old Trayvon Martin as a “suspicious person,” followed him, fought with him, and then fired a single bullet through his chest, after which he spun a “tangled web of lies” to justify his actions.

“‘Fucking punks. Those assholes, they always get away,’” said assistant state attorney John Guy as he stood in front of the packed court, using the same words that he says Zimmerman told a police dispatcher as he pursued Martin on the night of February 26, 2012. “Those were the words in that grown man's mouth as he followed in the dark a 17-year-old boy who he didn’t know ... Those were the words in that man’s chest when he got out of his car armed with a loaded semi-automatic pistol and two flashlights to follow on foot Trayvon Benjamin Martin, who was walking home from a 7-Eleven ... Those were the words in that defendant’s head moments before he pressed that pistol into Trayvon Martin’s chest and pulled that trigger.”

Zimmerman, now 29, who has lived in hiding since he was released on bail in June of last year, has pleaded not guilty to second-degree murder, claiming that he shot Martin in self-defense. He faces a potential sentence of life in prison if convicted. His trial is expected to last up to four weeks, during which jurors will be sequestered, due to the high-profile nature of the case.

Guy told the court that on the day of his murder, Martin had been staying at his father's girlfriend's house in a gated development known as the Retreat at Twin Lakes, and had spent the day playing videogames and “hanging out” with his girlfriend’s 12-year-old son, Chad Joseph. In the evening, he left to walk less than a mile to the 7-Eleven to get a can of soda and a bag of Skittles for Chad.

“Listen carefully to when the screaming stops,” Guy told jurors.

En route, Martin telephoned a female friend, who will testify how she heard him say to Zimmerman, “Why are you following me?” before the line went dead, Guy told the court. Meanwhile, Zimmerman, who lived in the development and volunteered as a neighborhood-watch representative, was trailing the boy while on the telephone to a police dispatcher, reporting the hoodie-wearing teenager as “suspicious” and telling her how there had been a spate of recent burglaries in the community. The recording of his call will be played in court, showing how "almost under his breath" he referred to Martin in derogatory terms, Guy said, then ignored an instruction from the dispatcher not to get out of his car and follow the boy.

The first two police officers to attend to Martin’s body found him face down, his hands clutched under his chest where he had been shot, and the ear buds from his cellphone lying next to his head. The victim’s father, Tracy Martin, wept quietly during the prosecutor’s description of his son lying dead in the street with officers stuffing a plastic Walmart bag into the bullet wound in his chest to try to stop air escaping as they attempted in vain to breathe life into him.

Zimmerman, wearing a dark suit and patterned tie, sat largely impassively in court, though appeared to gulp uncomfortably a couple of times as the call in which he described Martin to a dispatcher was played to the court.

Don West, co-counsel for the defense, said in his own opening statement: “The evidence will show that this is a sad case, that there are no monsters here ... George Zimmerman is not guilty of murder. He shot Trayvon Martin because he had to, in self-defense.”

Zimmerman, an insurance agent, had left his home that evening for a brief trip to a local Target store to buy supplies for his packed lunch to take to work the following day. As he drove through the community, he saw Martin—whom he did not know—entering the development “not through a gate, but cutting through the houses,” said West.

“Little did George Zimmerman know at the time that in less than 10 minutes from him first seeing Trayvon Martin that he, George Zimmerman, would be sucker-punched in the face, have his head pounded on concrete and wind up shooting and tragically killing Trayvon Martin,” he added. A charge of second-degree murder, he said, suggested “a ‘depraved mind’ act, ill will, hatred, spite,” but Zimmerman, he said, acted only to save his own life. Suggesting that the bellows for help heard in the background of a local resident’s 911 call were Zimmerman’s, and not those of his victim, he said: “George Zimmerman was crying out for help and no one helped. And it continued. It continued until you hear the shot. You hear the cries for help up until the moment of the shot and then there are no more cries for help. Why would there be?"

He added: “My guess is that the silence was deafening at that point.”

Since the summer of 2011, when residents formed a neighborhood-watch group in response to a rise in crime in their development, Zimmerman had acted as a point of liaison with Sanford police on behalf of the community. “Crime was on the rise, people were stealing things, there had even been a home invasion,” said West, adding that it was in that context that Zimmerman had been alert to what he perceived as a stranger acting suspiciously.

He “was not patrolling this night or any other night,” said West, adding that residents had been told by police that if they ever saw something suspicious, they should call in to report it—as Zimmerman did.

Local residents will testify that they saw Zimmerman straddling Martin on the ground—but, said West, that was after the fatal shot had been fired. As Martin fell forward, the right ventricle of his heart pierced by the bullet, Zimmerman was caught underneath him and had to scramble out from under the boy’s dying body, which is what residents saw, said West.

Addressing further testimony that will be presented by the prosecution, in which a local resident will describe Zimmerman as breathing hard and staggering after the shooting because he had just “had his butt kicked,” but that he also seemed strangely calm, Mr West said: “I submit that what George Zimmerman had just experienced was the most dramatic event of his life.”

Martin was a fit young man who had formerly played football as a linebacker and "knew how to give a hit and take a hit, as anybody does that plays football," said West. He "also knew how to mount someone to incapacitate them."

"If I've heard it once, I've heard it a thousand times, that Trayvon Martin was unarmed. What the evidence will show is that that is untrue. Trayvon Martin armed himself with a concrete sidewalk and used it to smash [Zimmerman’s] head, no different to if he had picked up a brick or bashed it against a wall. It's a deadly weapon," West said.

The prosecution's claim that there was a lack of blood or DNA evidence on Martin's hands "really can't be true," West said, suggesting that the medical examiner had possibly wiped it off inadvertently or simply failed to notice and record it. While some witnesses have told police that they saw Zimmerman straddling Martin, another has described seeing Martin straddling Zimmerman, he added. Showing the jury a photograph of Martin's pants, he pointed to dirt on the knees that he said indicated as much.

Judge Debra S. Nelson has barred prosecutors from producing voice analysts who would claim that shouts for help heard in the background of witnesses’ 911 calls belonged to Martin, after FBI experts hired by the defense testified at a pretrial hearing that the analysis was not reliable.

“Listen carefully to when the screaming stops,” Guy told jurors. “It’s right when the gunshot goes off ... You will know in your head and your heart and your stomach that George Zimmerman did not shoot Trayvon Martin because he had to. He shot him for all the wrong reasons: because he wanted to.”

Martin’s murder triggered a civil-rights outcry after Sanford police, a department with a history of checkered relations with the local black community, refused to arrest Zimmerman, citing his right to self-defense under Florida’s “stand your ground” law.

The victim’s parents launched a petition calling for his arrest and prosecution, which drew more than 2 million signatures, and a special prosecutor was ultimately appointed by Florida Gov. Rick Scott to examine the case. The special prosecutor filed a charge of second-degree murder.

Speaking at the courthouse this morning before the trial opened, Martin’s mother, Sybrina Fulton, said: “I am here today as Trayvon Martin’s mother. As I have been every day, I will be attending this court to try to get justice for my son. I ask that you pray for me and my family, as I don’t want any other mother to have to experience what I am going through now.”

Her ex-husband, Trayvon’s father, added: “We hold onto the memories that Trayvon left with us. We hold onto his smile, which strengthens us, and we ask that you all continue to pray for us.”