SANFORD, Fla. -- Despite a clamoring by some for a conviction against George Zimmerman, jurors acquitted the former neighborhood watch leader of all charges, leaving many Americans to wonder how the justice system allowed him to walk away from the fatal shooting of Trayvon Martin.
Part of the answer is found in the 27-page jury instructions on two matters: justifiable use of deadly force and reasonable doubt. Jurors were told Zimmerman was allowed to use deadly force when he shot Martin not only if he faced actually faced death or bodily harm, but also if he merely thought he did.
Reasonable doubt can come from conflicting evidence and testimony, which jurors heard plenty of over nearly three weeks.
Some Martin family supporters may never understand the gap between the legal basis for the jury's acquittal and what they perceived as the proper outcome: Zimmerman's conviction for either second-degree murder or manslaughter.
"There is a difference between the law and what people think is fundamentally justice," said Barbara Arnwine, president and executive director of the Lawyers' Committee for Civil Rights Under Law, a Washington-based civil rights group.
Under Florida law, jurors were told to judge whether Zimmerman was justified in using deadly force by the circumstances he was under when he fired his gun. The instructions they were given said they should take into account the physical capabilities of both Zimmerman, 29, and Martin, 17. And if they had any reasonable doubt on whether Zimmerman was justified in using deadly force, they should find him not guilty.
"Beyond a reasonable doubt" is the highest standard of proof prosecutors face in American criminal courts. It means the jurors believe there is no other logical explanation for what happened than the defendant is guilty. If faced with two plausible explanations for what happened, jurors are supposed to acquit.
"The danger facing George Zimmerman need not have been actual; however, to justify the use of deadly force, the appearance must have been so real that a reasonably cautious and prudent person ... would have believed the danger could be avoided only through the use of that force," the instruction read.
Jurors refused to talk to reporters after the verdict about how they reached their decision Saturday night. Their names are being kept secret until Judge Debra Nelson lifts an order protecting their identities.
After the verdict, Jacksonville State Attorney Angela Corey said the use of deadly force is often one of the toughest areas of the law for prosecutors. Gov. Rick Scott appointed her office to the case a few weeks after the shooting when local prosecutors didn't press charges.
She said that when a victim shoots a robber or rapist, the use of deadly force is clearly justifiable. In cases such as Zimmerman's, the lines get blurry.
"That's why this case was unique, in a sense, and that's why this case was difficult," she said.
Even defense attorneys, who use the law to their advantage, say the instruction for the justifiable use of deadly force can be confusing to jurors since there are so many elements to it. It's one of the longest instructions given jurors.
"The more complex the instruction, the more it benefits the defense," said Blaine McChesney, an Orlando defense attorney and former prosecutor with no connection to the Zimmerman case. "It's a very convoluted instruction, but it's the best they have."
Jurors were also told that reasonable doubt about Zimmerman's guilt could come from conflicting evidence or the lack of evidence.
Over three weeks of testimony, they received mounds of conflicting evidence and testimony of what happened on that rainy February 2012 night after Zimmerman spotted Martin walking in his townhouse complex after the teen bought Skittles candy and iced tea from a nearby 7-Eleven. He didn't recognize Martin, who lived in the Miami area and was visiting the home of his father's fiancee. The neighborhood had experienced burglaries and some people had reported the suspects seen fleeing were young black males, like Martin.
After calling police dispatchers, Zimmerman got out of his vehicle and followed Martin. He says Martin attacked him. Prosecutors disputed that. The evidence was unclear.
None of Zimmerman's neighbors saw or heard the entire fight, and eyewitnesses gave differing accounts of whether Zimmerman or Martin was on top. Martin's parents testified it was their son screaming for help on 911 calls made by Zimmerman's neighbors. Zimmerman's parents testified that no, it was their son. The fight ended seconds after the screams when Zimmerman fired one shot from his handgun into Martin's heart.
Zimmerman identifies as Hispanic. His mother is from Peru and his father is white. After the verdict, civil rights leader Al Sharpton asked the U.S. Justice Department to bring charges against Zimmerman for civil rights violations as it did against the Los Angeles police officers in the Rodney King police beating case two decades ago.
NAACP President Benjamin Todd Jealous concurred and started a petition calling for federal charges.
"The most fundamental of civil rights -- the right to life -- was violated the night George Zimmerman stalked and then took the life of Trayvon Martin," Jealous wrote in the petition, posted on the website MoveOn.org and addressed to Attorney General Eric Holder.
Holder may address the matter when he talks to NAACP members Tuesday at their national convention in Orlando.
But federal law probably doesn't apply, said David Weinstein, a former federal prosecutor in Miami. Unlike the police officers in the King case, Zimmerman wasn't acting "under color of law."
There also is little basis to charge Zimmerman with a federal hate crime, Weinstein said, since prosecutors would have to show that he shot and killed Martin primarily because of the teen's race. Nothing in the state trial suggested it was a racially motivated crime, he said.
"Under the law, there is no basis for them to file any charges," Weinstein said about the Department of Justice.
Under public pressure, he added, the Justice Department may send lawyers to Florida to investigate the case so they can write a report that says "there was nothing there."
"That may satisfy people," Weinstein said.