Investigators don't know where 15-year-old Sierra LaMar is, but they are almost certain she is dead.
For more than two months, the high school cheerleader's family has been holding out hope. They have organized repeated searches of the Northern California neighborhood where she disappeared and made numerous public appeals for help.
On Tuesday, even as authorities announced the arrest of a 21-year-old suspect on suspicion of murder, Marlene LaMar vowed not to stop looking for her daughter.
"Her body hasn't been found," Marlene LaMar said at a news conference, her voice breaking. "I believe there was a reason she wasn't found. We're not giving up on that."
But Santa Clara County Sheriff Laurie Smith said there was "direct and circumstantial" evidence that led investigators to believe that Antolin Garcia-Torres, 21, kidnapped and killed the Morgan Hill girl, who disappeared in March on her way to school.
Investigators think Garcia-Torres, a Morgan Hill resident, picked Sierra at random.
"We believe this is the worst kind of crime: a stranger abduction of a young girl," Smith said at Sheriff's Department headquarters in San Jose.
Investigators found the teenager's cellphone March 17, the day after she was last seen walking to her bus stop. The next day, they found a Juicy bag with her clothes folded neatly inside.
DNA was found on the items in the bag, Smith said. After receiving lab results March 28, Smith said, investigators identified Garcia-Torres — already in the system for a previous arrest — as their suspect and began around-the-clock surveillance.
"We needed additional information," Smith said. "We were hoping he would lead us to where Sierra was."
Smith did not elaborate on why detectives made the arrest Monday night at a Morgan Hill Safeway grocery store except to say that "public safety was our primary concern."
"Even though we had been surveilling him, surveillance is not perfect," she said. "We wanted to make sure this did not happen again."
After officials recovered Garcia-Torres' red Volkswagen Jetta, they found additional evidence linking him to Sierra, Smith said. She declined to elaborate on the evidence but said it did not include blood.
The DNA also connected Garcia-Torres to a March 2009 assault in Morgan Hill, Smith said. She did not disclose the specifics of that incident.
Garcia-Torres, who was previously convicted on a misdemeanor charge of interfering with a police officer, was also arrested but not prosecuted in connection with a felony assault. Smith said that the assault was not sexual, but that the arrest resulted in Garcia-Torres' inclusion in the DNA database used to identify him as a suspect.
Garcia-Torres' sister told the San Jose Mercury News, "It's not him."
"I honestly feel they don't have enough evidence to convict him," 26-year-old Lucero Garcia said.
Garcia said her brother is married with a young daughter. His wife is three months pregnant.
"It feels like we're in a movie right now," she said. "An unfair movie."
Several details are still not known about Sierra's disappearance, Smith said, including where her body is, how she was killed or when.
Other suspects were identified and watched during the investigation, Smith said, but detectives believe Garcia-Torres acted alone.
Although neither a weapon nor a body has been found, Smith said, investigators have "strong facts" indicating that Sierra was murdered.
"These are very, very difficult cases to prosecute, a homicide when you have not found a victim," she said. "But it has been done."
Marlene LaMar begged her daughter's suspected killer to "say where she is."
"Please, please give the information that you have to lead us to Sierra to help end this nightmare," she said.