KELLER -- A video the Verk family shared on social media shows their beloved and silly daughter Zuzu in her element -- giggling and smiling.

Lori Verk says that energy and light was present the last time she spoke to her daughter on the phone.

"She was very up, optimistic. She was stressed because she was studying for midterms," Lori recalls.

That conversation was 11 excruciating days ago. Lori and her husband Glenn formally reported their daughter Zuzu missing on Oct. 12, when they repeatedly couldn't reach her.

"Something wasn't right. Something wasn't right," her mother says.

The 21-year-old Keller woman's disappearance has launched a massive search in Alpine, where she's a student at Sul Ross State University.

"We’ve collected over 100 interviews and statements from potential witnesses," says Alpine Police Chief Russell Scown.

Authorities talked about their efforts Friday in a news conference they carried live on Facebook.

"We’ve gathered mounds of evidence including computers, cell phones, vehicles," Scown says.

The one thing they haven't been able to do, however, is talk to Zuzu's boyfriend.

"Unfortunately we have one individual who we believe does have information, who has refused to come and talk to us," Scown says.

Zuzu's family identifies the boyfriend as Robert Fabian, someone Zuzu has dated now for at least six months. Our call and email to his attorney were not returned Friday.

"We've invited him into our home. We've invited him into our hearts. At this point, we were hoping he'd be along side us in this search for her," Lori Verk says.

Hundreds of others are searching, however, and police are now asking people to even look in abandoned vehicles and trash piles.

A reward for Zuzu's whereabouts continues to grow. It's now at $100,000.

Zuzu Verk missing

"That just goes to show you how many people are concerned and want her back safe and sound, so we can all be back together," Lori says.