This story was published before Aaron Hernandez went on trial. It has been updated to reflect what's happened since then.

(CNN) Aaron Hernandez was destined to be a football superstar and was already one of the NFL's most promising tight ends.

But less than a year after signing a $40 million contract extension with the football powerhouse New England Patriots, he was charged with first-degree murder.

Two hours after his arrest on June 26, 2013, the Patriots dropped him from the team.

Jury selection for Hernandez's high-profile trial began in January, and the jury began its deliberations late Tuesday afternoon.

The way defense lawyer James Sultan laid it out for the Massachusetts jury in closing arguments, why would a young man with a $40 million contract kill semi-pro player Odin Lloyd less than a mile from his own home?

And friends and fans alike have wondered for a long time now: How could the star player who had more than 900 receiving yards in 2011 now be accused of murdering three people?

From 'golden boy' to behind bars

Long before Hernandez made national headlines, he was a standout athlete in Bristol, Connecticut, who came from a family described as a local sports dynasty.

"I don't think there was another family that was more familiar in Bristol," Bob Montgomery, who covers high school sports for the Bristol Press, told CNN.

The young Hernandez was the "golden boy," playing football, basketball and running track, following in the footsteps of his uncle, older brother and father -- all well-known athletes in the community.

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Hernandez's father constantly pushed his son, requiring him to practice for hours before he could go out with friends.

"I saw a closeness with them that I'd never seen before," Montgomery said of the relationship between Hernandez and his father.

But his father, the man who kept the 16-year-old anchored, died from complications after a routine surgery.

Hernandez left high school halfway through his senior year in January 2007 to join the University of Florida Gators, and trouble seemed to follow.

In just his first semester, a police report says Hernandez got into a fight at an off-campus restaurant, sucker-punching the manager and rupturing his eardrum.

The following fall, there was a shooting near a local club. Police reports link Hernandez and several other University of Florida football players to an argument in the parking lot.

Hernandez was one of more than 20 people interviewed by police, and he was the only one who did not make a statement after invoking his right to counsel.

At the time, Hernandez's mother told the Orlando Sentinel newspaper , "I know he was at the club, but he never saw any shooting."

The case remains open, and no one has been charged.

Issue of marijuana

Hernandez was also suspended at least once for marijuana, an issue that would follow him as he entered the draft his junior year.

Trying to put the alleged drug use behind him, Hernandez wrote a letter to the Patriots' director of personnel.

"If you draft me as a member of the New England Patriots, I will willfully submit to a bi-weekly drug test throughout my rookie season. ... In addition, I will tie any guaranteed portion of my 2010 compensation to these drug tests and reimburse the team a pro-rata amount for any failed drug test," he wrote, according to the Boston Globe.

Before the draft, Hernandez was expected to be a first or second round pick. He was passed over until the fourth round, when the Patriots selected him.

By the end of the second season, he was a bona fide star, inking the five-year contract extension worth $40 million.

One month before signing the deal, however, he was partying at a Boston club. That same night, two men from the club were found dead.

Did spilled drink lead to slaying?

Investigators allege Hernandez shot and killed Daniel Abreu and Safiro Furtado on July 16, 2012, because one bumped into him on a nightclub dance floor and spilled his drink.

District Attorney Patrick Haggan described the scene, saying Hernandez became "angered and increasingly agitated, particularly after Mr. Abreu smiled and did not apologize."

Hernandez's friend tried to calm him down, and the pair walked outside and eventually entered a second club across the street, the prosecutor said. Court documents identify that friend as Alexander Bradley, who would go on to accuse Hernandez of shooting him in the eye in an incident that would take place seven months later.

After leaving the second nightclub, Hernandez and the friend returned to their SUV and pulled over on a nearby street where Hernandez removed a revolver from the engine block, Haggan said.

Hernandez began trailing Abreu, Furtado and three of their friends in his SUV, authorities said.

He then pulled up to the victims' car at a red light and leaned out the driver's side window with a loaded revolver, Haggan told the court.

Hernandez allegedly said, "Yo, what's up now," followed by a racial slur, and fired at least five rounds from a .38-caliber revolver, Haggan said.

Abreu, the driver, was shot several times and fatally hit in the chest. Furtado was sitting in the front passenger seat and suffered multiple gunshot wounds, including one to the head, Haggan said.

Hernandez was charged in the double homicide just last month, and he pleaded not guilty. Investigators found evidence they believe links him to the 2012 slayings while investigating an entirely different case -- the slaying of Odin Lloyd.

The killing of Odin Lloyd

In the early hours of June 17, 2013, Lloyd was shot seven times. The semi-pro football player's body was found by a jogger the next afternoon in an industrial park in North Attleboro, Massachusetts.

Lloyd, who was dating the sister of Hernandez's fiancee, had been partying with Hernandez just before his death, his friends told CNN.

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Prosecutors say Lloyd was last seen with Hernandez and Hernandez's two associates, Carlos Ortiz and Ernest Wallace, around 2:30 a.m. in a rented silver Nissan Altima.

Surveillance video from security cameras at an industrial park showed an Altima heading toward a secluded area at 3:22 a.m.

At the same time, chilling text messages from Lloyd's phone were sent to his sister telling her he was with "Nfl," adding, "just so u know."

Between 3:23 and 3:27 a.m., workers nearby reported hearing gunshots. At 3:29, a camera showed an Altima pulling into Hernandez's driveway, about a half a mile from the death scene.

Three people got out of the car, and Lloyd was not one of them.

Nine days later, Hernandez was arrested and charged with first-degree murder and other weapon-related charges. He has pleaded not guilty.

One of the incidents involved Lloyd seeing guns and ammunition stored at Hernandez' so-called flop house, his apartment in Franklin, Massachusetts. The other thing that set off Hernandez was a conversation Lloyd had with two men at a club earlier that night, June 14, 2013, a source tells CNN.

The cumulative effect apparently reached a breaking point for reasons that most people would find inconsequential. The source would not say what that was, but compared it to something as insignificant as the spilled drink that allegedly led to the 2012 Boston double slaying.

Lloyd's killing did not involve possible knowledge of that double slaying as investigators previously considered, the source added.

Photos: Athletes charged with murder Photos: Athletes charged with murder Convicted murderer and former NFL star Aaron Hernandez was found hanged in his Massachusetts prison cell Wednesday morning, officials said, just days after his acquittal in a separate double murder case Hide Caption 1 of 9 Photos: Athletes charged with murder South African sprinter Oscar Pistorius was charged with murdering his girlfriend, model Reeva Steenkamp, in February 2013. Pistorius, the first double-amputee runner to compete in the Olympics, was convicted of murder and sentenced to six years in prison. Hide Caption 2 of 9 Photos: Athletes charged with murder Lawrence Phillips, a former NFL running back who was awaiting trial on charges of killing his prison cellmate last year, died in January after being found unresponsive in his prison cell, the California Department of Corrections and Rehabilitation said. The death of Phillips, 40, was being investigated as a suicide, the department said. Phillips was sent to a California prison in 2008 after being convicted of domestic violence, false imprisonment and vehicle theft charges. While serving a 31-year sentence, authorities say, he killed his cellmate in April 2015. A trial was anticipated in Kern County, California. Hide Caption 3 of 9 Photos: Athletes charged with murder Rae Carruth , who was a wide receiver for the Carolina Panthers, became the first active NFL player ever charged with first-degree murder. His pregnant girlfriend, Cherica Adams, was killed in December 1999, and prosecutors said he arranged for her to be killed in a drive-by shooting. Carruth was eventually convicted of conspiring in her murder, and he is now in prison. The unborn child, a boy, survived. Hide Caption 4 of 9 Photos: Athletes charged with murder Middleweight boxer Rubin Carter , known as "Hurricane" in the ring, served 18 years in prison for a triple homicide in a bar in 1966. A federal judge overturned his sentence and that of his alleged accomplice, John Artis, in 1985, ruling that the conviction was based on "racial stereotypes, fears and prejudices." Hide Caption 5 of 9 Photos: Athletes charged with murder Groundbreaking skateboarder Mark "Gator" Rogowski confessed to beating and raping Jessica Bergsten, then choking her to death and burying her in the desert in 1991. Bergsten was a friend of Rogowski's former girlfriend, and Rogowski testified that he acted out of misplaced anger against his ex. Rogowski was denied parole in 2011 and will not be eligible for parole again until 2018. Hide Caption 6 of 9 Photos: Athletes charged with murder Baltimore Ravens linebacker Ray Lewis and two others were charged with murder in 2000 after a fight in a popular Atlanta bar district left two men dead on the street. The murder charges against Lewis were dropped after he pleaded guilty to a misdemeanor charge of obstruction of justice and testified against his friends; they were later acquitted. Lewis announced his retirement before helping the Ravens win the Super Bowl in 2013. Hide Caption 7 of 9 Photos: Athletes charged with murder Bruno Fernandes das Dores de Souza , a former goalie for the Brazilian soccer club Flamengo, was convicted in March 2013 for the murder of his ex-girlfriend. He was sentenced to 22 years and three months for the murder of Eliza Samudio, who disappeared in 2010. Souza, his current girlfriend and his ex-wife were among nine people charged with torturing and murdering Samudio, who had been trying to prove Souza had fathered her son. Hide Caption 8 of 9 Photos: Athletes charged with murder Although O.J. Simpson was found not guilty, the former football star's 1995 murder trial has kept him a household name. Simpson was acquitted in the death of his wife, Nicole Brown Simpson, and Ron Goldman. In October 2008, Simpson was sentenced to 33 years in prison on multiple counts, including armed robbery and kidnapping, in connection with a robbery at a Las Vegas hotel in 2007. Hide Caption 9 of 9

Life in a jail cell

For the past 10 months, Hernandez has been behind bars in a 7-by-10 foot cell. Sheriff Thomas Hodgson, who runs the jail where Hernandez is incarcerated, says he has talked to inmate No. 174954 at length.

Hernandez, Hodgson says, spends his time reading the Bible and another book he suggested, "Tuesdays With Morrie."

Hodgson has encouraged Hernandez to turn to his childhood anchor, his late father. The father-son relationship has come up in their conversations and could have played a role in his checkered past.

"His dad clearly kept him grounded," Hodgson said. "When you lose that person and there's no one there to help you process it in a healthy way, at 16 you're going to reach out to anybody that's older than you to deal with it."

Even behind bars, Hernandez has found trouble. He has been accused of getting into a physical altercation with another inmate and is facing charges of assault and threatening a guard's life.

That's on top of three murder charges, the lawsuit claiming he shot his friend in the face and three civil suits from the families of his alleged victims, among other things.

As for the Lloyd case, Hernandez's lawyers contend the circumstantial evidence is full of gaps.

"There's certainly a lot of what I would call smoke. There's no doubt about it," defense lawyer Jamie Sultan said during a June 16, 2014 hearing. "But that's not probable cause that he committed murder. And you can't just throw a bunch of stuff against the wall and say that's good enough."

No murder weapon has been found, and while at one point it seemed likely that Ortiz would be a key witness against Hernandez, there are now serious questions about his credibility.

Hernandez's lawyers and mother declined to be interviewed, but both predict he will be cleared. It's a possibility that haunts Lloyd's loved ones.

"That's my biggest fear," Michael Branch, Lloyd's former coach and mentor, said. "All it takes is one juror."