Prosecutors called Zimmerman a liar and portrayed him was a "wannabe cop" vigilante who had grown frustrated by break-ins in his neighborhood committed primarily by young black men. Zimmerman assumed Martin was up to no good and took the law into his own hands, prosecutors said.
State Attorney Angela Corey said after the verdict that she believed second-degree murder was the appropriate charge because Zimmerman's mindset "fit the bill of second-degree murder."
"We charged what we believed we could prove," Corey said.
As the verdict drew near, police and city leaders in the Orlando suburb of Sanford and other parts of Florida said they were taking precautions against the possibility of mass protests or unrest in the event of an acquittal.
"There is no party in this case who wants to see any violence," Seminole County Sheriff Don Eslinger said immediately after jurors began deliberating. "We have an expectation upon this announcement that our community will continue to act peacefully."
The verdict came a year and a half after civil rights protesters angrily demanded Zimmerman be prosecuted.
Zimmerman wasn't arrested for 44 days after the Feb. 26, 2012, shooting as police in Sanford insisted that Florida's Stand Your Ground law on self-defense prohibited them from bringing charges. Florida gives people wide latitude to use deadly force if they fear death or bodily harm.
Martin's parents, along with civil rights leaders such as the Revs. Jesse Jackson and Al Sharpton, argued that Zimmerman whose father is white and whose mother is Hispanic had racially profiled their son. And they accused investigators of dragging their feet because Martin was a black teenager.
Before a special prosecutor assigned to the case ordered Zimmerman's arrest, thousands of protesters gathered in Sanford, Miami, New York and elsewhere, many wearing hoodies like the one Martin had on the night he died. They also carried Skittles and a can of iced tea, items Martin had in his pocket. President Barack Obama weighed in, saying that if he had a son, "he'd look like Trayvon."
Despite the racially charged nature of the case, race was barely mentioned at the trial. Even after the verdict, prosecutors said race was not about race.
"This case has never been about race or the right to bear arms," Corey said. "We believe this case all along was about boundaries, and George Zimmerman exceeded those boundaries."
One exception was the testimony of Rachel Jeantel, the Miami teen who was talking to Martin by phone moments before he was shot. She said he described being followed by a "creepy-ass cracker" as he walked through the neighborhood.
Jeantel gave some of the trial's most riveting testimony. She said she overheard Martin demand, "What are you following me for?" and then yell, "Get off! Get off!" before his cellphone went dead.
The jurors had to sort out clashing testimony from 56 witnesses in all, including police, neighbors, friends and family members.
For example, witnesses who got fleeting glimpses of the fight in the darkness gave differing accounts of who was on top. And Martin's parents and Zimmerman's parents both claimed that the person heard screaming for help in the background of a neighbor's 911 call was their son. Numerous other relatives and friends weighed in, too, as the recording was played over and over in court. Zimmerman had cuts and scrapes on his face and the back of his head, but prosecutors suggested the injuries were not serious.
To secure a second-degree murder conviction, prosecutors had to convince the jury that Zimmerman acted with a "depraved" state of mind that is, with ill will, hatred or spite. Prosecutors said he demonstrated that when he muttered, "F punks. These a-. They always get away" during a call to police as he watched Martin walk through his neighborhood.
To win a manslaughter conviction, prosecutors had to convince the jury only that Zimmerman killed without lawful justification.
Zimmerman, Martin families react on Twitter
The families of George Zimmerman and Trayvon Martin are reacting on Twitter after the former neighborhood watch volunteer was cleared of all charges in the fatal shooting of the unarmed black teen.
Zimmerman's brother, Robert Zimmerman Jr., says his family is relieved that the jury found George Zimmerman not guilty of second-degree murder and manslaughter. He tweeted: "Today ... I'm proud to be an American."
Martin's parents, Tracy Martin and Sybrina Fulton, were reserved but expressed their disappointment. Fulton expressed her faith in God, saying "Lord during my darkest hour I lean on you." Tracy Martin tweeted that he was broken-hearted, but that his faith is "unshattered."
The teen's brother, Jahvaris Fulton, said simply: "Et tu America?" a reference to the Latin phrase "Et tu, Brute?" known as an expression of betrayal.
The Associated Press
Questions jurors considered in Zimmerman trial
Here are five questions jurors weighed during their deliberations.
Whose screams are on 911 calls? • Convincing jurors about whose voice is screaming for help on 911 calls that captured audio of the fight was the primary goal of prosecutors and defense attorneys. Martin's mother, father and brother testified it's the Miami teen screaming for help on recordings of the 911 calls made by Zimmerman's neighbors. Zimmerman's mother, uncle, father and five friends told jurors it was the neighborhood watch volunteer's voice. One of Zimmerman's neighbors, Jayne Surdyka, says the screams were those of a boy.
Who was on top? • Zimmerman was wearing a red jacket, and Martin had on a dark hoodie. Zimmerman's former neighbor Jonathan Good, perhaps the witness with the best view of what happened, says he saw a person in dark clothing straddling someone in red or white clothing and making downward movements with his fists in a mixed-martial arts maneuver known as "ground and pound." Neighbors Selma Mora and Surdyka say the person on top got up after the shooting. Zimmerman's attorneys say Zimmerman had been on the bottom but got on top of Martin after he fired his gun.
How did position of Martin's arms change? • Zimmerman told investigators that Martin was on top of him, pounding his head into the pavement. After he fired his gun, he says, he got on top of Martin and spread his arms. However, a photo taken moments later by Zimmerman's neighbor shows Martin's arms under his body. Defense expert Vincent DiMaio testified Martin could have moved his arms in the 10 to 15 seconds he would have been conscious after being shot in the heart.
Did Zimmerman act in self-defense? • Zimmerman has argued all along he acted in self-defense, although he passed up chance for a self-defense "stand your ground" hearing in which a judge could have thrown out the case without it going to a jury if the judge was convinced there was enough evidence to support it. Zimmerman's community college instructor, Alexis Francisco Carter, told jurors that a person can claim self-defense if they have a reasonable fear of death or great bodily harm. In their jury instructions, jurors were told self-defense is justified in using deadly force if Zimmerman reasonably believed that such force was necessary to prevent imminent death or great bodily harm to himself.
Did Zimmerman act with ill will, hatred, spite or evil intent? • To get a second-degree murder conviction, prosecutors needed to show that Zimmerman acted with ill will, hatred, spite or evil intent. Prosecutors argued that profanities Zimmerman uttered under his breath while he watched Martin walk through his neighborhood were evidence of ill will and hatred. But when asked by prosecutors and defense attorneys, no witness said Zimmerman acted with these traits. The judge presiding over the case also allowed jurors to consider the lesser charge of manslaughter. To get a manslaughter conviction, prosecutors were required to show that Zimmerman killed without lawful justification.
The Associated Press