Details of Disappearance
Sierra left her home in the vicinity of Santa Teresa Avenue and Dougherty Avenue in Morgan Hill, California at 6:00 a.m. on March 16, 2012. She was going to walk to the bus stop to catch a 7:35 bus to Ann Sobrato High School, where she was a sophomore and a cheerleader.
Sierra texted a friend at 7:11 and agreed to meet her before class started. She never boarded her bus, never arrived at school and never met her friend. Her mother found out she was missing that evening when the school contacted her to say saying Sierra had missed class. She has never been heard from again.
On March 17, Sierra's cellular phone was found on the roadside about three-quarters of a mile from her home; it appeared to have been tossed from a passing vehicle. A day after that, the police found her bag in a cactus field on the roadside about two miles from the bus stop and one mile from where her phone was found. The bag had Sierra's pants and t-shirt folded and placed inside it.
In May, two months after Sierra was last seen, authorities arrested Antolin Garcia-Torres for her kidnapping and murder. Investigators stated they had both circumstantial and direct evidence against the suspect, including DNA evidence from his car, which police had seized in early April, and from Sierra's bag.
Photos of Garcia-Torres and his vehicle, a red and black Volkswagen Jetta, are posted with this case summary. Police found strands of Sierra's DNA inside his car, a strand of her hair on some rope in the trunk, and DNA from Garcia-Torres on her discarded clothing. He has a prior criminal record, but not for any sex assaults or felonies.
Police believe Sierra's presumed murder was a random act of violence; although she and Garcia-Torres lived just seven miles apart, there's no evidence the two ever met prior to her disappearance.
At Garcia-Torres's trial in May 2017, his defense argued Sierra was an unhappy teenager who had simply run away from home. He was convicted of her murder and also of three counts of attempted kidnapping; he had tried to abduct three other women from Safeway store parking lots in 2009, something the prosecution called "training" for Sierra's death.
Garcia-Torres was sentenced to life in prison; he could have faced the death penalty.
Sierra was born and raised in Fremont, California and previously attended high school there. Her parents divorced before her disappearance and she lived with her mother and her mother's boyfriend. They had moved to Morgan Hill only about six months before Sierra disappeared. She has no history of running away. Foul play is suspected in her case due to the circumstances involved.