The Santa Clara County District Attorney and Sierra's family were stunned the same jury that convicted Garcia-Torres of kidnapping and murdering the teenager opted to spare his life.
During a press conference, Sierra's father spoke saying: "I would be lying if I didn't say I am disappointed in the verdict. He'll be able to live, Sierra won't. He'll be able to breathe. Sierra doesn't. He'll be able to eat everyday, see his family, and we don't have that," Steve LaMar said. "The crime I thought deserved the maximum sentence, not the minimum."
WATCH VIDEO: Antolin Garcia-Torres spared death penalty in Sierra LaMar case
Garcia-Torres was found guilty of kidnapping and killing 15-year-old Sierra, who disappeared near her Morgan Hill home on her way to school on March 16, 2012. Her cell phone and clothing were found in the days after, but her body has never been found, despite an army of volunteers conducting searches that continue to today.
However, Garcia-Torres never testified on his behalf during the 13-week long murder trial.
Garcia-Torres was also found guilty last month for Taser attacks and the attempted kidnapping of three other women.
Defense attorneys had argued for the lesser penalty, suggesting that Garcia-Torres might have been exposed to pesticides while growing up in semi-rural San Martin. It was also argued that he grew up in a troubled family.
The prosecution had asked the jury for the death penalty to fit the nature of the crime.
FULL VIDEO: Officials discuss sentencing for Antolin Garcia-Torres in Sierra LaMar murder case
The penalty phase of the trial began May 16, a week after Garcia-Torres was found guilty of the missing teen's murder on March 16, 2012.
TIMELINE: Sierra Lamar kidnapping, murder case
Garcia-Torres was arrested two months after Sierra's disappearance when his DNA was found on her clothing, which was recovered in a field near her bus stop.
During the penalty phase of the trial, Garcia-Torres' mother, sister and cousins testified about the poverty, abuse, incest, neglect, loss, incarceration and addiction that have afflicted the defendant and his family throughout his life.
The defense presented the mitigating evidence in order to evoke sympathy for Garcia-Torres, but was not legally allowed to present it as an explanation for the crimes committed.
Garcia Torres' attorneys will be back to court they said to appeal the verdict in September, but the family hopes he has a change of heart. "In that cold-hearted murderers heart I call on him today to tell us where Sierra is, so we can bring her home," Santa Clara County Sheriff Laurie Smith said.
"The angst will be in our lives forever. Nothing will ever take that away," Sierra's mother Marlene LaMar said.
Sierra's mother said they're planning a memorial this summer to give them some closure.
Click here for full coverage on the Sierra Lamar case.
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Bay City News contributed to this story.