Are Three Missing Aspiring Models From Colorado Linked?

By Ken Lee

02/28/2013 at 07:30 PM EST

From left: Raven Cassidy Furlong, Kara Nichols and Kelsie Schelling

Courtesy Raven Cassidy Furlong, Kara Nichols, Kelsie Schelling

On Tuesday afternoon, Lin Furlong of Denver, Colo., received a troubling call from her stepdaughter, Raven, 17, who'd been missing since Feb. 5.

"Raven said she was safe, but that she was calling from someone else's phone and couldn't stay on the line and had to go," Lin Furlong tells PEOPLE. "I was relieved to hear her voice, but I'm terrified for her. She sounded scared and not like herself at all."

Raven had been using the modeling website Model Mayhem – a networking site for models and photographers – and her family believes her disappearance may have been linked to a stranger she could have met through the site.

Raven's story is all too familiar for the family of Kara Nichols, 19, of Colorado Springs. Kara, who also used the site, has been missing since Oct. 9 after she told roommates she was headed to a modeling job in Denver.

"We're reluctant to portray our daughter as just a no-good person that no one should care about," her mother Julia Nichols tells PEOPLE. She was informed by police that Kara had a connection to drug use and prostitution.

"She's our daughter. We love her dearly," Nichols adds. "We're deeply alarmed about what may have happened to her."

A third woman, Kelsie Schelling, 22, of Denver, who went missing Feb. 4, was also an aspiring model, according to her profile found on ExpertTalent.com. A representative of that site, however, tells PEOPLE that Schelling created the profile in May 2006 and only logged on once. So far, police say there's no conclusive evidence that the disappearances are related.

"Kara Nichols's case remains an active and ongoing investigation," Lt. Jeff Kramer of the El Paso County, Colo., Sheriff's Office tells PEOPLE. "We cannot say whether Model Mayhem was responsible at this time. We continue to investigate all leads."

Model Mayhem has allegedly been linked to the disappearances of at least 13 women, according to Michelle Bart, president of the National Women's Coalition Against Violence & Exploitation, which is now representing Raven and Kara's families.

"We feel there's an epidemic of young women being preyed upon on this site and it needs to be seriously investigated," says Bart, who points out the Better Business Bureau rated the site an F.

According to a statement released by Model Mayhem, the site "strongly believes that safety should be top of mind when doing anything online. Model Mayhem tries to educate users about scams and how to avoid them."

Adds Lin Furlong, who concedes that Raven has run away from home in the past: "We just want her to come home."

Anyone with information on Raven Furlong should email tips@nwcave.org or visit Facebook.com/HelpFindRavenCassidyFurlong. For Kara Nichols, email tips@nwcave.org, or visit Facebook.com/HelpUsFindKaraNichols. For Kelsie Schelling, call Detective Neal Robertson of the Pueblo County Sheriffs at (719)-553-2470 or visit Facebook.com/HelpFindKelsie.