The sheriff's office says it withheld the information until it could confirm that the bag and the clothes belonged to Sierra. They say DNA analysis of the items did not reveal any DNA or trace evidence that could point them to a suspect or person of interest.
Search and rescue teams are spread out over a three-mile radius from Sierra's rural Morgan Hill home. The intense effort follows the new discovery. Volunteer searchers found her pink and black Juicy brand purse with a pair of pants, tee-shirt, and undergarments inside. "The clothing was neatly folded inside her Juicy bag. What we do not know at this point is if she was wearing that particular set of clothes when she left the house or if it was extra clothing that she packed," Sgt. Jose Cardoza with the Santa Clara County Sheriff's Office said.
For Sierra's family, the developments are far from comforting.
"It doesn't necessarily point to either direction you know, whether she planned to run away or she was abducted or taken against her will," Sierra's father, Steve LaMar said.
"Each thing we are finding it gets scarier because she wouldn't purposely leave that stuff behind, so obviously there's more anxiety for us," Sierra's sister, Danielle LaMar said.
Sheriff Laurie Smith says her office is working with several known facts about Sierra's sudden disappearance Friday morning. The 15-year-old sent out a tweet from her home computer at 6:29 that morning. It was learned Thursday that she sent a text from her cellphone to a friend at 7:11 a.m. "She usually leaves for school between 7:10 and 7:15, so we don't know where her physical location was at the time. She texted a friend, a friend answered, and no further," Smith said.
So, Sierra usually leaves her house to catch the school bus at 7:25 a.m. Her cellphone was found Saturday 20 to 30 feet off the road at an intersection in the opposite direction of the bus. On Sunday, a trained search member found her purse with the clothing even further north near the intersection of Laguna and Santa Teresa.
Now, some 40 search and rescue personal and five trained dogs are looking for more evidence and are scouring outbuildings and abandoned structures. "They become places where you can hide something, where you can place it out of sight from the public, and so we have to check for that," explained searcher Jeff Thomas. "Even no result is a result. It tells us something about where she isn't and that allows us to move on to other places to continue to look."
So far, Sierra's disappearance is still classified as a missing person's case. "All cards are still on the table, possible abduction, human trafficking, voluntary runaway... We just don't know and we cannot confirm simply until we get information or evidence to prove otherwise," Cardoza said.
Cardoza also confirmed that the FBI is assisting in the case, but would not elaborate on specifically what role the agency is playing.
The sheriff's department says another search is tentatively scheduled for Saturday.
ABC7's Lilian Kim contributed to this report.