Sierra LaMar's parents said Tuesday that – despite what authorities were saying about the suspect arrested in connection with her disappearance – they are still hopeful that their daughter will be found alive.

Normally the Sierra Search Center isn't open on days when no active searches are scheduled. But because of the Monday night arrest of suspect Antolin Garcia-Torres, organizers unlocked the doors so volunteers could gather and console each other.

The mood inside the center was somber as volunteers trickled in and hugged each other.

While many were ecstatic that an arrest has been made, they did not expect authorities to announce Sierra had been murdered.

"We all came in here with swollen eyes, watery eyes, smeared makeup," said search volunteer Emma Spencer. "We are all just devastated. When we all came together, it was really touching because we all comforted each other."

At a sheriff's news conference Tuesday morning, Sierra’s mother Marlene LaMar said she's not giving up hope since her daughter's body has not been found.

"I do have a plea to the perpetrator; to please give information that you have to lead us to Sierra to help end this nightmare," said Marlene LaMar.

News of the murder charge and an arrest quickly spread at Sobrato High School, where Sierra was a student. Grief counselors were on campus to help classmates.

Parents there were glad someone is in custody.

"Just put him away. What he's done…the poor mom and dad," said a Sobrato High parent. "I feel so sorry for them."

Steve LaMar spoke exclusively to KTVU on Tuesday. He said Monday was the first time investigators told him they believe his daughter is no longer alive. 

"I'm kind of in a surreal shock state," said the missing teen’s father. "It was tough to hear. We're still hoping somehow they're wrong."

At Washington High in Fremont, where Sierra went to school last year, friends were also clinging to a sliver of hope. 

"I believe she's still alive and out there and until there's a body found, nothing can tell me otherwise," said friend Alexia Isom.

Sierra's best friend Channah Foreman showed KTVU a matching bracelet the two got at Disneyland just a year ago.

"[It] just reminds me of her," said Foreman. "Hers says 'Siela' for Sierra LaMar and mine is 'Cheefo,' because I'm Channah Foreman."

Foreman told KTVU that she has felt like part of her has been missing since her friend disappeared.

"It feels like someone grabbed my heart took a part of it and is refusing to let go of it," said Forman.

Volunteers said the best way they can help the family is by continuing to search for Sierra.

Klaas Kids founder Marc Klaas said it is critical for people to continue to search, because right now the suspect holds the power.

"He's got a bargaining chip," explained Klaas. "He can plea down in exchange for her remains. We need to remove that bargaining chip from him."

Meanwhile, the family of the Garcia-Torres claimed he has been wrongly accused.

Laura Torres, the mother of Garcia-Torres, said Tuesday she asked her son before his arrest Monday whether he had anything to do with the case, and he said he had never seen victim Sierra LaMar or had contact with her.

Torres described her son as quiet and respectful.    

Garcia-Torres's sister, Lucero Garcia, told the San Jose Mercury News that authorities had the wrong man.

Sheriff's officials said Garcia-Torres was arrested after Sierra's DNA was found in his vehicle and his DNA was found in Sierra's bag.

Laura Torres said she and her son were aware that they were under surveillance by authorities in the days before his arrest.