(CNN) — Opening statements begin Monday in the trial of George Zimmerman, a neighborhood watch captain accused of fatally shooting 17-year-old Trayvon Martin on February 26, 2012, in Sanford, Florida. Zimmerman is charged with second-degree murder. He says he shot the unarmed teen in self-defense.
A jury of six women will decide Zimmerman's fate, which has already drawn some scrutiny from the public about whether he will get a fair trial.
When he called 911 on the night of the shooting, Zimmerman was warned against pursuing Martin but did so anyway. The prosecution wanted to present a series of 911 calls as evidence that could establish who was heard screaming for help, but Judge Debra Nelson ruled against expert testimony on the calls due to the conclusion that the quality of the audio makes it impossible to tell whose voice is heard in the background. The 911 calls still may be played in court, and witnesses familiar with the voices of Zimmerman and Martin may testify about who is heard screaming.
Zimmerman's defense team looked grim as it announced it was out of money in late May, but it was able to raise over $40,000, thanks to outside donations.
The case has also triggered a national debate about gun use and race. Martin was black and Zimmerman identifies himself as Hispanic.
Trayvon Martin: The victim
Trayvon Martin was born on February 5, 1995, to Sybrina Fulton and Tracy Martin, who divorced in 1999.
Prior to the shooting, Trayvon Martin was living with his mother and his older brother in Miami Gardens, Florida, where he was a student at Dr. Michael Krop Senior High School.
The high school junior had been suspended from school three times: once for writing graffiti on a door, another time for missing school, and the last time after marijuana residue was found in his book bag.
Following his 10-day suspension in February 2012, Martin went to Sanford to visit his father at the home of his father's girlfriend, who lived in the Retreat at Twin Lakes. He was there for seven days prior to his death.
After Martin was killed, the medical examiner who conducted Martin's autopsy said the teen had traces of THC -- an active ingredient in marijuana -- in his system when he died.
Despite his school suspensions and alleged previous drug use, Sybrina Fulton told CNN's Anderson Cooper that her son was a normal teen who "loved playing football ... basketball ... loved to eat everything in your house."
George Zimmerman: The defendant
George Zimmerman, now 29, was working as a neighborhood watch captain in the gated community where Martin was staying temporarily when he died.
In 2003, Zimmerman enrolled at the Seminole State College in Florida and earned a vocational certificate as an insurance agent.
Prior to his marriage to Shellie Nicole Dean in 2007, Zimmerman and his then-fiancee both filed domestic violence protection orders against each other. A 2005 scuffle involved pushing and punching, according to police.
From 2009 to 2012, Zimmerman was enrolled at Seminole State College, working toward an associate degree in general studies.
He was arrested on one count of second-degree murder on April 11, 2012, for killing Martin.
If convicted of second-degree murder, Zimmerman could face 25 years to life in prison.
Important events leading up to the shooting
In July 2005, Zimmerman was arrested for an assault on an officer and resisting arrest after an incident at a local bar. Zimmerman claimed the case was the result of mistaken identity. He entered a six-month pretrial diversion program as part of a plea deal in that case.
In October 2005, Florida passed the "Stand Your Ground" law, allowing its citizens to meet "force with force" if they believe they or someone else is in danger of being seriously harmed by an assailant.
In 2008, Zimmerman attended a four-month law enforcement program. In his application for the course, Zimmerman wrote, "I hold law enforcement officers in the highest regard and I hope one day to become one."
Timeline: Zimmerman's reports involving suspicious activity in neighborhood
On August 4, 2011, Zimmerman submitted his first report to the Sanford Police Department about a suspicious black male walking around in the Retreat at Twin Lakes neighborhood, where he served as a neighborhood watch captain.
The next day, Zimmerman called the SPD again, reporting another suspicious black male lurking in the area.
On October 6 of that year, Zimmerman called in a third report, again alerting authorities to a suspicious black male.
On February 2, 2012, Zimmerman called in a similar report to the SPD.
"According to all records checks, all of Zimmerman's suspicious persons calls while residing in the Retreat at Twins Lakes neighborhood have identified black males as the subjects in the matter," the Sanford Police Department said in a statement after Martin was killed.
The night of the shooting
On February 26, 2012, Zimmerman left his home in his car to go to a store. The 28-year-old called the SPD's non-emergency line to report "a suspicious person" in the neighborhood. Officials instructed him not to get out of his car or approach the person.
Moments later, neighbors reported hearing gunfire.
Just before he was killed, Trayvon Martin was walking back from a nearby convenience store, headed to his father's girlfriend's home. He was carrying a small amount of cash, candy, a soft drink and a phone. He was not carrying a gun.
When police arrived, Zimmerman admitted to authorities that he shot the teen, but said it was in self-defense.
In his police report, Officer Timothy Smith noted that Zimmerman was bleeding from the nose and back of his head after the shooting.
Responding officers were not able to identify Martin when they arrived at the crime scene because he was not carrying identification. His body was transported to the morgue.
After the shooting
The day after the shooting, Martin's father filed a missing person report after his son failed to return home. Officers with the SPD visited Tracy Martin, who later identified his son's body using a picture.
Investigators received a fax from the Altamonte Family Medical Practice on March 8 containing the medical records identifying the injuries sustained by Zimmerman the night of the shooting.
In mid-March of that year, the FBI received a report that Zimmerman had contacted a gun store about acquiring a new firearm because, according to Zimmerman, his "life is in danger, and he needs more guns."
Despite nationwide criticism that an arrest had not yet been made, Sanford Police Chief Bill Lee stated in March of that year that Zimmerman had not been charged with a crime because there were no grounds to disprove his version of events.
On March 15, Zimmerman's father, Robert Zimmerman, wrote a letter to the Orlando Sentinel, stating that his son had been unfairly portrayed as a racist. He noted that his son is Hispanic and grew up in a multiracial family.
The next day, authorities released seven 911 calls from the night of the shooting. In one of the recordings, a voice screams, "Help, help!" followed by the sound of a gunshot.
On March 19, the U.S. Justice Department and the FBI announced they had launched an investigation into Martin's death.
Days later, Benjamin Crump, the attorney for the Martin family, held a news conference stating that Trayvon Martin was on the phone with his girlfriend around the time he was killed. According to Crump, the girl stated she heard someone ask Martin what he was doing, followed by Martin asking that person why he was following him.
On March 22, a petition on Change.org -- created by Trayvon Martin's parents and calling for the arrest of George Zimmerman -- surpassed 1.3 million supporters.
That same day, Lee announced he was stepping down "temporarily" as head of the police department, which had been criticized for its handling of the case.
In April, Zimmerman was charged with second-degree murder.
Zimmerman attended his bond hearing on April 20 with defense attorney Mark O'Mara. During that hearing, Zimmerman apologized to Martin's family for the loss of their son.
On April 23, Zimmerman was released on bail. A judge accepted his written plea of not guilty days after his release.
A medical report by Zimmerman's family doctor, made the day after the shooting, was made public on May 15. The report stated Zimmerman was diagnosed with a fractured nose, two black eyes and two lacerations to the back of his head.
On June 1, Zimmerman was ordered to surrender within 48 hours after a judge revoked his bond, following the prosecution's argument that Zimmerman and his wife allegedly misrepresented their finances when his bond was originally set in April. Two days later, Zimmerman surrendered to authorities and was taken into custody for a second time.
Zimmerman's jail stint ended a few days later, when he was released after posting the required 10% of his $1 million bond.
In July 2012, Zimmerman gave his first public interview to Fox News' "The Sean Hannity Show." During that interview, Zimmerman stated he would not have done anything differently the night of the shooting.
In April of 2013, Zimmerman waived his right to a "Stand Your Ground" pretrial immunity hearing.
In early May, Zimmerman's defense lawyers and prosecutors faced off in a pivotal hearing. A judge declared that most of the information regarding Martin's and Zimmerman's background would be barred from the trial, including Martin's school suspension history.