SAN JOSE -- The man charged in the presumed killing and disappearance of 15-year-old Sierra LaMar was indicted on the strength of recovered DNA and alleged self-incriminating statements that revealed knowledge about evidence before detectives knew it themselves.

That was the thrust of the case that compelled at least 12 of 18 members of a criminal grand jury to indict Antolin Garcia-Torres in the murder of Sierra, whose body still has not been found, and in three prior attacks on women that surfaced after his 2012 arrest in the teen's case.

The new details about the evidence against Garcia-Torres are contained in 1,900 pages of secret grand jury testimony released late Friday. This newspaper bore the cost and successfully fought to make the transcript public as Garcia-Torres' attorneys sought to keep it under wraps. Before the release of the transcript, little was publicly known about Garcia-Torres' arrest other than that it was based on DNA evidence.

"It's vital for the public to understand what occurred during the secret grand jury proceeding, particularly since the prosecution is seeking the death penalty in this case," said David J. Butler, editor and senior vice president for news at the Bay Area News Group.

Garcia-Torres' defense team could not be immediately reached late Friday.

Sierra disappeared March 16, 2012 while walking to a school bus stop near her home in an unincorporated area near Morgan Hill. While Sierra's body has not been found despite exhaustive searches by officials, family and volunteers, prosecutors believe they have a strong enough case to seek the death penalty -- the first such case in the county since District Attorney Jeff Rosen was elected in 2011.

Sierra's DNA was found inside the suspect's car, while his was on her clothing, discarded in a field not far from where she was headed on the foggy morning when she disappeared.

More specifically, testimony from 50 witnesses painted a picture that included the discovery of DNA consistent with Garcia-Torres on LaMar's pants, which first led Santa Clara County Sheriff's detectives to suspect him. A hair from Sierra was found on a rope inside his car trunk, and black polyester fibers from the floor were similar to fibers found on her clothing.

During one of multiple interviews with sex-crimes detectives, Garcia-Torres preemptively tried to explain away the evidence against him. That peculiarity, they testified, continued to the point where Garcia-Torres was giving them new insight into the crime.

When the detectives mentioned they had DNA evidence, Garcia-Torres purportedly told them that on the way to a fishing trip at the Uvas or Chesbro reservoirs, he masturbated and ejaculated into a tissue and threw it out the window, which he claimed was a regular practice. But the detectives had not yet specified that the trace DNA they found was from semen.

"When you answer questions you were not asked, that is a telltale marker of a guilty conscience," said Steven Clark, a criminal-defense attorney, legal analyst and former Santa Clara County prosecutor.

Deputy District Attorney David Boyd also pointed out detectives' testimony that Garcia-Torres, again unsolicited, laid out an unusual route toward the reservoirs that took him to Palm Avenue near where Sierra disappeared, even though it's in the opposite direction, and claimed to have had no interaction with the teen.

It was a clinching moment for investigators: Garcia-Torres contending that he never crossed paths with Sierra but still going out of his way to explain how their DNA ended up on each other's person or property.

"The defense now will have to do two things: create doubt based on other possible scenarios of DNA transfer and also fix that big lie which is, 'I never met Sierra LaMar,'" Clark said. "There's a lot of lawyering left to do, but the defense has its work cut out for it."

Other elements of the case that had not been made public until Friday was the finding that Garcia-Torres had purchased bleach and a turkey baster three days before Sierra vanished.

"He purchased two items. One of which can destroy DNA, and the other can be used as an applicator," Boyd said to the grand jury, according to the transcript.

That prompted testimony from Garcia-Torres' wife refuting that implication by claiming he would not have purchased those items without her consent. Also according to the grand jury transcript, she provided an alibi for Garcia-Torres that ultimately did not withstand scrutiny.

Authorities also testified that the condition of Sierra's recovered clothing suggested foul play.

"That sweatshirt, when it's recovered has dirt stains on it, and where are those dirt stains? They are on the inside of that sweatshirt, when you lift it up. And there's also dirt stains on the back of her jeans," Boyd said during the proceedings. "Now how does that happen? And I want you to envision this in your mind. Sierra's rear-end and back are on the ground and someone's got her feet by their hands and they are dragging her."

He also said that based on video evidence from a trailer park and a bank, Garcia-Torres had about six hours to commit the crime.

"That's a lot of time to hide a body in whatever way needs to be hidden," Boyd said.

The sheer volume of detail is vital to the prosecution's case, Clark said, given that Sierra still has not been found.

"What the DA's saying is we don't have the body of Sierra LaMar, but we have the footprint and the trail," Clark said. "They have a lot of forensic evidence that pieces together to show a very sinister demise."

Before his arrest, detectives tracked Garcia-Torres' moves with a GPS device placed on his Volkswagen Jetta and scoured the Morgan Hill trailer he shared with his mother, pregnant wife and toddler daughter. He was questioned several times and surveilled around the clock for nearly two months by detectives who had pegged him as a suspect since shortly after Sierra's disappearance.

They made the arrest on May 21, 2012, when they no longer believed there was a possibility that Garcia-Torres would lead them to Sierra.

The grand jury heard testimony related not only to Sierra's case, but also a series of violent attacks on three South Bay women in 2009. He is charged with trying to kidnap them in separate carjackings that were linked to him after his fingerprint was found in a stun gun dropped during one of the encounters.

The Feb. 11 indictment meant that Garcia-Torres is going directly to trial, instead of a preliminary hearing in which a judge determines whether there is enough evidence to warrant bringing the case before a jury. In numerous court dates, his attorneys put off entering a plea.

Days after the indictment, he pleaded not guilty to all charges.

Garcia-Torres' attorney Brian Matthews did not want the grand jury transcript released because he believed news reports about it would hamper his client's chances of getting a fair trial.

However, a judge sided with a request by this newspaper to unseal the 1,900-page transcript on Friday, unless the defendant's lawyers convinced an appellate court to review the ruling. The paper had argued that the public's right to view court documents bore more weight than the defendant's fear of pre-trial publicity.

While such concerns could prompt the defense to seek a change of venue for the trial, the paper's attorneys said the transcript's release was not likely to significantly pollute the jury pool in a county of 1.8 million people.

But it will further engage the active minds of those who have been following the case closely, Clark said.

"It's almost become a murder mystery that's captivated Santa Clara County and we're all participants in it. It's not hard to see why they returned an indictment."

Contact Robert Salonga at rsalonga@mercurynews.com. Contact Eric Kurhi at ekurhi@mercurynews.com.