Jury deliberating penalty phase in Sierra Lamar murder trial, Garcia-Torres facing death

SAN JOSE, Calif. (KGO) -- Wednesday was the first full day of deliberations in the penalty phase of the Sierra Lamar murder trial.

Jurors will decide whether to impose the death penalty or life in prison without parole on the missing teen's killer.

TIMELINE: Sierra Lamar kidnapping, murder case

Antolin Garcia-Torres, 26, was convicted May 9 of the first-degree murder of the 15-year-old in 2012 and of the attempted kidnappings of three women in two dark Morgan Hill Safeway parking lots in 2009.

In his closing argument this afternoon, defense attorney Brian Matthews responded to prosecutor David Boyd's remark that Garcia-Torres did not deserve the mercy or compassion of a life sentence.

"I am asking you to exercise mercy, and I'm proud to say that," Matthews said. "Mercy's a good thing. Mercy's an important thing. It ennobles the giver."

RELATED: Defense calls first witness in penalty phase of Sierra Lamar trial

Matthews reiterated the poverty, abuse, neglect, incest and loss that characterized Garcia-Torres' home life growing up in ramshackle homes in San Martin, where his parents, who married in Michoacan, Mexico when his mother was 13, picked strawberries.

Garcia-Torres father, Genaro Garcia Fernandez, an alcoholic who the defendant's mother testified was physically and emotionally abusive to her, is serving a life sentence for the sexual abuse of a young female relative.

RELATED: Tears flow as parents of Sierra Lamar give victim impact statements

The defendant's mother, Laura Torres, testified last week that Garcia Fernandez hit her on three occasions when she was pregnant with Garcia-Torres and threatened to kill Torres and the children after Garcia-Torres was born.

But the horrors that Garcia-Torres' family faced during his childhood did not all affect him directly, Boyd argued this morning. The defense has not claimed that the defendant himself was abused.

Additionally, the defense cannot present information about Garcia-Torres' childhood as an explanation for the crimes committed. It is simply presented as sympathetic evidence.

"Antolin's story is not that of a person who was given all the advantages in life and then did something horrible," Matthews said.

"He was raised in poverty. That's a reason for life. He experienced childhood neglect. That's a reason for life," Matthews said. "He was exposed to abuse. That's a reason for life. He was exposed to violence. That's a reason for life."

While the jury's guilty verdict indicates that prosecutors proved Garcia-Torres involvement in Sierra's death beyond a reasonable doubt, Matthews emphasized that any lingering doubt should be cause for a life sentence.

"The prosecution talks about what could have happened to Sierra, about unmentionable things that happened to Sierra," Matthews said. "They're asking you to speculate, to guess."

"Was her death a tragic accident? If it was, that certainly would be a reason to vote for life," Matthews said.

Bay City News contributed to this report.

Click here for full coverage on the Sierra Lamar case.