ABC News

Police have found a bag and clothing belonging to Sierra LaMar, the Northern California teenager who has been missing for almost seven days.

The 15-year-old was last seen Friday morning as she headed off  to school from her Morgan Hills home.

Police  found the bag on Sunday but didn't release that information until Thursday, because they had to confirm it belonged to Sierra, Santa Clara County Sheriff's Sgt. Jose Cardoza said. They made the find near an intersection two miles from her home.

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

He  told ABC News that police were treating her disappearance  as a missing person's case. "There is no information leading us to believe she purposely ran away," he said. "On the other hand, we don't have information or evidence associating a crime with her being missing."

The teen's family and friends held candlelight vigils for Sierra this week.

Investigators found Sierra's cell phone on the side of a road in the opposite direction of her bus stop on Saturday. Sierra's mother, Marlene LaMar, told ABC News that her daughter's bus driver said she never got on the bus the morning she disappeared.

The charger for the teen's cell phone was found in her room at home, and the phone looked as if it had been tossed.

Authorities said the phone yielded no clues, nor did investigators find any helpful clues on her computer.

"I can't imagine Sierra without her cell phone," her mother told ABC News after her daughter's phone was found. "That's when it became a harsh reality."

More than 150 tips have been called in to authorities, but none have yielded new leads in the case, authorities said.

Sierra's father, Steve LaMar, told ABC News he had no reason to believe Sierra was planning to run away. He said there was "nothing out of the ordinary" about her behavior leading up to her disappearance.

He talked to her the day before she was reported missing, and she was "happy, talking to me about homework. She was asking me to make an appointment so she could dye her hair," LaMar told ABC News. "She wouldn't miss that appointment - if you knew my daughter."

Marlene LaMar became worried when daughter did not  return home from school Friday.

Sierra's parents reached out to her friends, and grew more anxious when one friend said Sierra wasn't in class earlier that day. They decided to contact authorities around 5 p.m. Friday, after her high school sent them an email saying Sierra  hadn't shown up for school that day.

Sierra's parents are divorced, and she lived with her father in Fremont, Calif., until October, when she moved in with her mother and transferred to Sobrata High School in Morgan Hills.

ABC News has learned that Steve LaMar is a registered sex offender and is currently on probation for committing lewd and lascivious acts with a child under 14 years of age. Police have emphasized that Steve LaMar is not a suspect in the investigation.

Police have questioned students at both Sierra's current high school and the previous school she attended in Fremont, Cardoza said. They have interviewed more than 100 people and have broadened the investigation to include all known sex offenders in the immediate and broader area of the teen's home.

Sierra is 5 feet, 2 inches tall. She has long brown hair, and was last seen carrying a pink-and-black purse.

The Associated Press contributed to this report.