(CNN) In Hollywood, there's no better magnet for stargazing than a movie premiere. So on a Sunday afternoon in late June, the summer sun couldn't keep thousands of fans from lining Hollywood Boulevard, hoping to spot a star.

This was the "Terminator Genisys" premiere , and only one star mattered: Arnold Schwarzenegger . The former governor of California shook hands, signed autographs and posed for selfies. It's the kind of personal attention Fred and Kathy Santos wish they could get from Schwarzenegger , who they say stole justice from their dead son.

"He plays a hero in the movies, yet in real life he's not a hero," Fred Santos said. "He's a dirty politician."

Minutes before ending his two terms as governor, Schwarzenegger issued his final act: Commuting the sentence of Esteban Nunez, the teen who pleaded guilty to stabbing to death the Santos' son, Luis, in 2008.

It's not that a governor issuing clemency was anything new. But neither the Santos family nor San Diego County prosecutors had any idea it was coming, let alone got a chance to plead their case. Instead, they were informed by a news release and a phone call from a reporter.

"My son (was) stabbed in the heart when he was alive," Fred Santos told CNN. "Schwarzenegger stabbed him in the back after my son is killed."

At first, Fred Santos asked himself why the governor would care about their case. But deep down he knew. Santos feared political influence from the beginning -- ever since learning that Esteban Nunez wasn't just any accused killer.

He was the son of Fabian Nunez, California's most powerful Democrat and a political ally to the governor. So to many, such as San Diego County District Attorney Bonnie Dumanis, Schwarzenegger's surprise commutation appeared as if Nunez was cashing in.

"I think it was political cronyism at its worst."

The speaker's son, a brutal crime

When Fabian Nunez was sworn in as speaker of the California Assembly in 2004, his son was by his side. At 15, Esteban Nunez appeared baby-faced and shy -- nothing like the muscular, tattooed adult described in court records just four years later.

It was October 2008, and prosecutors alleged that Esteban Nunez and Ryan Jett were fueling their anger with alcohol. They had just been denied entry to a fraternity party near the campus of San Diego State University (neither were students there), and they were looking for revenge. The Sacramento natives were going to show them how it was done "in Sac town," the pair boasted, according to court records.

"They decided they were going to either burn a frat house or they were going to stab some people," Dumanis said.

Armed with knives, they walked the streets at 2 a.m. until they encountered Luis Santos and a friend. After an initial altercation, Luis called several more friends who ran to his aid.

"It was a melee basically, where two of the boys were stabbed. One went into an induced coma," Dumanis said. "Luis was stabbed, and one got smashed in the eye."

"My boy's dying, my boy's dying," Luis' friend screamed to a 911 dispatcher.

"Stay awake Luis, stay awake," another friend sobbed.

A knife pierced the left ventricle of Luis' heart. He died at the scene.

Later that same night, Nunez, Jett and two others piled into a car and headed north to Sacramento. Surveillance video at a 7-Eleven captured Jett and Nunez leaving the store with a Big Gulp cup. They filled it with $1.30 worth of gasoline and used it to burn their weapons and bloody clothes, throwing the items into the Sacramento River and agreeing to never speak of the incident.

But witnesses helped police identify four suspects, and two of them weren't so quiet. The pair fingered Nunez and Jett as the stabbers, later getting probation in exchange for their testimony.

Two months after getting a phone call that their son was dead, the phone rang again at the home of Fred and Kathy Santos. Their son's alleged killers were behind bars, and a reporter had a question: What was their reaction to the son of Fabian Nunez being arrested for Luis' murder?

"My concern was that politics might interfere with justice in the legal system," Fred Santos told CNN.

Though assured the system would not bend to politics, Santos says he grew up in Asia, where "politicians are dirty."

"I asked if the judge was a Democrat," he said, believing Fabian Nunez's power in that party would influence the case.

The judge was a Republican. In time, however, the judge would become the least of Santos' worries.

Foes to friends

By the time Esteban Nunez was charged with murder, his father had already derailed Arnold Schwarzenegger's early years in office. The Republican governor tried to bypass Nunez and the Democrats by calling for too many special elections on pet projects, with failing results.

"I got to tell you, things are very sloppy here on the first floor," Nunez once told reporters, referring to the governor's office.

Schwarzenegger returned the jab in private conversations that were recorded and later released to news organizations.

"Fabian is too much a political operator," he told his staff, apparently unaware of the recording. "Not so much passion about specific things he stands for."

But with his policies stalling in Sacramento, Schwarzenegger announced a shift in strategy in a State of the State address, conceding his mistakes and pledging to work with Nunez and the Democrats. The tactic proved beneficial for both sides. The pair stood side-by-side when California passed legislation creating the highest minimum wage in the nation, one of many victories out of a newly minted political friendship.

In 2008, though, Schwarzenegger did not publicly get involved in Nunez's personal problems. Instead, with his son facing a first degree murder charge and fighting for a lower bail amount, Fabian Nunez called on his Democratic friends to vouch for the credibility of his son. A union leader, a retired assemblyman and even then-Los Angeles Mayor Antonio Villaraigosa submitted letters to the judge.

On official mayoral stationery, Villaraigosa wrote that Esteban had shared meals at his home and that he was "a young man of good and upright character."

"They already have the mayor trying to influence the judge," Fred Santos said. "Nobody in power was speaking (for us). We're just regular folks."

The deal

In 2010, Esteban Nunez and Ryan Jett were moments away from their murder trial. A first degree conviction would result in a sentence of 25 years to life in prison. A second degree conviction, 15 to life.

But then, with jury selection already underway, came the next twist in this case: a plea deal for Nunez and Jett. If the pair pleaded guilty to voluntary manslaughter, they would face a maximum of 16 years behind bars. For the Santos family it sounded too brief, but would offer swift justice and an end to years of future pain.

"So we will not be spending the rest of our lives going to court ... listening to them fight their appeal if they were convicted," Fred Santos said.

For District Attorney Dumanis, a plea bargain also removed, in her mind, the only impediment to an otherwise airtight case: proving who actually stabbed Luis.

Witness testimony pointed to Jett as Luis' killer, while Nunez stabbed two other boys who survived. Was that enough to pin first- or second-degree murder on Esteban Nunez? The question no longer needed an answer when all sides agreed to a deal. Nunez and Jett pleaded guilty to voluntary manslaughter.

"I couldn't believe we were giving this case away," said Rick Clabby, then deputy district attorney, in an interview with CNN.

Now retired, Clabby believes the evidence was strong enough for at least a second-degree murder conviction.

"We charged Nunez with conspiracy, too," Clabby said. "It didn't matter if the jury couldn't decide who was the stabber."

But Dumanis stressed the emotional toll on the victims and approved the deal.

As part of the plea, Nunez admitted that his actions led to the death of Luis Santos. Both Nunez and Jett were sentenced to the maximum of 16 years in prison.

Calling it "bitter satisfaction," the Santoses thought their son's newly confessed killers would go away quietly and pay for their crimes, content with the plea deal they had just reached.

"Had I known what was going to happen," said Dumanis, "that (deal) never would have been an agreement."

The governor's final act

On January 2, 2011, six months after their son's convicted killers were sent to prison, the phone rang at the home of Fred and Kathy Santos. It was another reporter.

"That's been the story of our life, a reporter calls the house and gives me information," said Kathy Santos.

This time, she was told of the surprise commutation and immediately went online for more information.

"There was Esteban's face," she said, "with a little blurb about Arnold's dirty deed."

Minutes before leaving office, Schwarzenegger announced the commutation in an emailed news release. Esteban Nunez's sentence had been cut in half. He would be eligible for release in April of 2016.

"I was so disgusted," Kathy Santos said. "Esteban has been coddled, he hasn't had to be accountable because apparently his father has gotten him off."

Fabian Nunez has publicly denied he forced Schwarzenegger into granting a favor, but he also wasn't complaining. Nunez has repeatedly maintained that his son got a raw deal because he was related to a powerful lawmaker.

"From the beginning, my son was the headliner in the case," Nunez told CNN affiliate KCRA in 2011. He declined CNN's repeated requests for an interview, but after an initial version of this story aired on television, Nunez spoke to CNN over the phone.

"This has gone from aiding and abetting to him being labeled a killer," Nunez said of his son.

He argues that comments from the Santos family, their attorneys and the district attorney's office have boiled the case down to a convenient narrative: Esteban Nunez accepted a plea deal, then had it cut in half because of the influence of his father. In reality, Fabian Nunez told CNN, "the case is more complicated," and that his son sought clemency to right wrongs perpetrated on them by an "overzealous district attorney" and a "conservative judge."

"My son did not want to take the deal" if it meant he had to accept 16 years behind bars, Nunez said. "He was going to go to trial" and defend his position that Esteban was not nearly the aggressor that the prosecution was making him out to be.

"This was a fight among a large group" of people, Fabian Nunez said, adding that the two suspects who were given probation in exchange for their testimony "were just as responsible as my son."

In a letter to the court objecting to the sentence, Fabian Nunez claims the judge overreached in giving Esteban the full 16 years because his son, unlike Jett, "had no criminal record" and that Esteban "did not harm Mr. Santos," referring to the witness who claimed Jett inflicted the fatal blow.

Fabian Nunez went on to claim his son was misled by the judge, who "told us that (he) would treat Esteban differently" from Jett.

"He told the attorney one thing in chambers, then went into open court and said another," Fabian Nunez told CNN.

Prosecutors maintain they warned Esteban in open court that he could receive 16 years.

The judge denied that he made conflicting statements and refused to reconsider the sentence.

Esteban Nunez and his attorneys continued their fight until December 6, when they submitted a motion to end their appeal.

Less than a month later, Nunez received clemency.

"I believe Nunez's sentence is excessive," wrote Schwarzenegger in his commutation letter, citing the lack of criminal history and the inability to prove that Nunez actually stabbed Luis Santos.

"It was a complete betrayal of a system of justice and fairness," said Dumanis, the district attorney, who questions whether Nunez even submitted a clemency application to the governor. Nunez's attorney, Charles Sevilla, told CNN he did but refused to release it.

Upon his exit, Schwarzenegger ordered all clemency files sealed for 25 years. (That's not necessarily unusual. Schwarzenegger's predecessor, Gray Davis, did the same thing.)

In his only comment about the case, Schwarzenegger told Newsweek, "There's criticism out there. I think it's just because of our (Fabian Nunez) working relationship and all that. It maybe was kind of saying, 'That's why he did it.' Well, hello! I mean, of course you help a friend."

Fabian Nunez told CNN he was told by Schwarzenegger that the comments were "taken out of context." Still, the Santos family attorney, Nina Solarno, was outraged.

"He took a political favor and played God, and took justice away from this family," claimed Solarno, who is also a board member for the advocacy group Crime Victims United.

In a private letter to the Santos family, Schwarzenegger wrote: "I recognize that the last minute nature of my final acts as Governor provided you no notice, no time to prepare for or absorb the impact of this decision. For that, I apologize."

It was an apology the Santos family would not accept.

Taking on the Terminator

While Arnold Schwarzenegger returned to Hollywood in 2011, Fred and Kathy Santos returned to court. Along with the San Diego County district attorney, they filed suit alleging Gov. Schwarzenegger violated "Marsy's Law," which mandates that victims' families be given a right to speak in all proceedings related to their case.

It was the last chance Dumanis had to keep Esteban Nunez behind bars and repair the damage from what she considered a tremor shaking the entire system.

"When a governor commutes a sentence in such a flagrantly political way, it puts everybody in the system on notice that their (deals) are not safe," Dumanis said.

While agreeing Schwarzenegger's move was "grossly unjust" and "deserving of censure," two separate judges concluded that it was not illegal and that "Marsy's Law" applied to parole hearings, not executive clemency.

Schwarzenegger, for now, had won. But both the Santoses and San Diego prosecutors were not giving up.

They succeeded in changing the state law, which now requires California governors to give victims and prosecutors at least 10 days of notice before issuing clemency. That will ensure Luis Santos' case isn't repeated, but it won't keep Esteban Nunez from being released.

While the Santos family will next petition the state Supreme Court, they know time is running out.

"Esteban is going to be out before we get to the Supreme Court," Solarno conceded. "Now we want an acknowledgment that the family's rights were taken from them, that they should have been heard, and that from this day forward your case is setting precedent that other victims are going to be heard."

Arnold Schwarzenegger did not respond to CNN's requests for a formal interview, but when questioned by CNN at the "Terminator Genysis" premiere in June, he would not speak about the case.

"Since we're here today for the movie promotion, we talk movies," he said.

"That's the type of person he is," said Fred Santos. "He thinks somebody being murdered -- it's news that is below his status."

"I get their pain," Fabian Nunez said, adding that his attempt to reach out to the Santos family wasn't accepted. "I get to see my son, they don't get to see theirs ... but I make no apologies for fighting for justice for my son."

For Rick Clabby, the vocal former prosecutor, the Santos family has been victimized too many times in this case.

"They were victimized when their son was murdered, they were victimized when our office made this stupid decision and they were victimized when the governor buddied up with Mr. Nunez," Clabby told CNN.

But Fred and Kathy Santos say they'll continue to fight. They're not sure where it will lead them, but they know they have to keep trying.

"We weren't there to protect Luis, to prevent him from being killed," Fred Santos said. "This is the only thing we can do for him."