Detectives are combing the internet records of missing teen Amber Dubois in hopes of finding some clues about her disappearance. They're also examining several new pieces of evidence they found over the weekend.

The girl was last seen Feb. 13 as she walked to Escondido High School.

Sheriff's officials told KFMB-TV they found several items of clothing that will be analyzed during the week to see if they can be helpful in the search for the girl.

The North County Times reported that police subpoenaed cell phone and computer usage records recently and found that Amber was more active than usual in online chats the week before she disappeared.

Amber's father, Maurice DuBois, said Amber's disappearance has taken a toll on her family. The girl's 5-year-old half-sister is in counseling and Amber's mother struggles every day, he said. Her parents, who are divorced, haven't worked since Amber disappeared.

There's a $55,000 reward for anyone with information leading to her safe return and an additional $10,000 reward for information leading to the arrest of anyone responsible for her disappearance.

A search is scheduled every day, but investigators don't disclose where they are sending people to look. The command center houses a closed-off room with maps marked with search areas.

Since Amber's disappearance was so mysterious, there is a chance the girl was abducted by someone she knew, Dubois said.

Police and Amber's father have no strong theories on how she disappeared.