Sierra's mother has requested the help of Marc Klaas, whose 12-year-old daughter Polly was kidnapped and killed in Petaluma in 1994. He now heads the KlaasKids Foundation.
"We are prepared to offer everything, from support and counseling to full pledged search recovery efforts," said Klaas. "We will be sending our search director to Morgan Hill to establish a physical presence, a search center."
Sheriff's investigators said they have followed up on 150 tips from the public. Some of them were possible sightings of Sierra without any positive results. They also say forensic analysis of her cellphone and computer did not reveal any useful information.
Klaas and Tonya Miller are on opposite sides of the Bay Area, but are now linked by one goal -- finding Sierra. The petite 15-year-old has been missing since Friday morning and her case is getting national attention. The KlaasKids Foundation will coordinate with law enforcement to carry out searches. Miller is busy supporting Sierras mother who has been active in the investigation since day one.
"We've got a meal schedule going, we're trying to make sure Marlene eating, we're going to try to make sure she gets rest at night because she is going to get sick if she doesn't," said Miller.
Residents of Morgan Hill are already doing what they can - flyers are seemingly everywhere, like one, at a yoga studio owned by Wendy Mosgrove.
"I think about her every minute of the day. I pray for her constantly and her family. I'm so sad. It's like we have lost a child. The whole community feels like we have lost a child," said Mosgrove.
Mary Gutierrez lives in Gilroy, is a captain with the San Jose Fire Department and speaks for many in the South Bay and across the Bay Area.
"When I saw it on TV the other night, it practically brought my husband and I to tears, he is also a firefighter and the profession that we have, we see so much and we love to take care of children and we can't even imagine how it is for the community and the people that it is affecting," said Gilroy resident Mary Gutierrez.
Hundreds attended a vigil for Sierra Tuesday night at the Morgan Hill Presbyterian Church.
"...Just realize how much I love you and want you back. Want you back," said Marlene at the vigil.
"Sierra we love you and can't wait for you to come home," said Sierra's father, Steven LaMar at the vigil.
Between now and Sierra's hoped for return, Marc Klaas had this advice for Sierra's mother: "I told her that she needed to take care of herself, and try and get some rest, and try and get some food on a regular basis and try to not give up hope."
Sierra had a regular routine of catching the school bus every morning at an intersection near her rural Morgan Hill home. The only clue is her cellphone found less than a mile away.
Klaas believes Sierra was also taken against her will.
"Somebody was probably stalking her, laying in wait for her and took advantage of the situation at hand," said Klaas.
Detectives have already conducted more than 100 interviews, they've talked to registered sex offenders in the area, neighbors and friends and classmates. Hundreds of people came together for the candlelight vigil and so many people on holding onto that feeling of hope and support.
"It was wonderful, but today is like the emotional exhaustion sets in and I'm just really worried," said Miller.
The worry and the wait are taking their toll. A reward fund is being set up and will be announced soon. There is another candlelight vigil tonight, this one in Fremont, where Sierra and her mother used to live.
Both the family and investigators are hoping for the public's help solving this case. Anyone with information can contact the Anonymous Tip Line at 408-808-4431, or you can email tips regarding Sierra.