There is a potential new lead in the search for a Morgan Hill teenager who went missing nearly two years ago.
A Santa Clara County Sheriff's Office dive team returned to a South Bay lake Thursday, looking for evidence in the case of 15-year-old Sierra Lamar, who disappeared while on her way to school.
Official word from the sheriff's headquarters is that the divers were training when NBC Bay Area spotted them Wednesday. But sources close to the case said the divers were actually looking for evidence in the case.
NBC Bay Area is not naming the lake or its location to protect the integrity of the investigation.
"They're out here doing something," said Mark Garcia, a private investigator helping the Lamar family find Sierra.
Sources tell NBC Bay Area divers are using a new, powerful sonar that allows them to better locate a body in murky waters.
"These guys are the best of the best, the sheriff's dive team," Garcia said. "That's a nice piece of equipment they have."
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MORE: Heartbreaking Milestone in Sierra Lamar Disappearance
Sources also said Thursday was the second time divers were at the particular lake -- a lake that is of high interest to investigators.
Legal analyst Steven Clark said a murder conviction without a body is extremely difficult.
"It is critical to the prosecution because as long as Sierra's body is not found, the defense is going to say this is a missing persons case," Clark said.
Antolin Garcia Torres is currently in jail and has been charged with murder in Sierra's case.
"This investigation has been ongoing since the beginning," Clark said. "That will continue until Sierra's body is found or until the trial is concluded."
MORE: Sierra Lamar Murder, Kidnapping Suspect Appears in Court
Garcia Torres, who has refused to enter a plea in the case, appeared in Santa Clara County Superior Court last month. He again refused to enter a plea at that hearing.
His public defender at the January hearing told the judge the defense was “making progress,” but still had more evidence to review.
Garcia Torres is scheduled to return to court on March 3. At that time, a preliminary hearing will be set, and Garcia Torres is expected to enter a plea, a judge said.
The ongoing delay is characterized in court documents (PDF) as a back-and-forth between prosecutors and defense attorneys over the sharing of evidence.
Prosecutors say they have DNA evidence linking Garcia Torres to the crime but Lamar’s body has never been found.
