(Image Credit: ABC News)

The 2-week-old investigation into California teenager Sierra LaMar's puzzling disappearance is now being viewed as a possible abduction.

Santa Clara Sheriff's Office Sgt. Jose Cardoza told ABC News today that authorities now believe LaMar, 15, may have been abducted or kidnapped, or that she voluntarily left home but is now being held against her will.

"The first week the focus was on the public's help for possible sightings," Cardoza said. "Now the focus is to call us with people that are suspicious in the neighborhood. We don't know where she could be in the area, but we are thinking that whoever is involved either lives in Morgan Hills area or has a familiarity with the area."

The LaMar family is growing desperate as the days pass while no new information about their daughter's whereabouts has emerged. "We have made pleas on camera," said Steve LaMar, the teen's father, "if there is someone that is holding her, release her.  We don't care about anything except getting Sierra back home."

"Just release her, leave her at a gas station, anything, we just want her home," LaMar said.

Sierra, described as "bubbly" and "loving," was last seen by her mother at 6 a.m. on March 16, before she left for school. LaMar's mother realized she was missing after she did not return home from school that day. Her school bus driver later said that the teen never got on the bus that morning.

While LaMar's disappearance was originally treated as a missing persons case, the teen's parents never believed she ran away.

Cardoza agrees. "There are no indications that she would have run away, and no other leads point towards that she would run away," Cardoza told ABC News.

Searchers found her cell phone a day after her disappearance and a bag of her clothes were found last week.

The cell phone was found alongside the road about a mile away from her home in Morgan Hills, Calif., in the opposite direction of her bus stop. The charger for her cell phone was found in her room at home. Police said the phone looked as if he had been tossed. A forensic investigation of the phone yielded no leads, neither did a search of her computer.

Though LaMar's mother knew something was seriously wrong when the phone was found.

Sgt. Cardoza said her Juicy brand bag contained a neatly folded pair of pants and a T-shirt, but this evidence also provided no clues about whether LaMar was abducted or ran away.

LaMar is described as 5 feet 2, with long brown hair. Her father told ABC News she loves listening to music and was a cheerleader at her old school.

"We want you to come back home, we know you will find your way back to us," said Marlene LaMar, Sierra LaMar's mother, at a candlelight vigil last Friday.