Sierra LaMar has been missing for more than a month, and police say they have found some new leads and are expanding their search in the California case. 

The 15-year-old Morgan Hill, Calif., girl went missing on March 16, when she was last seen heading from her home to a nearby school bus stop, where she never arrived, according to authorities.

Santa Clara County Sheriff's Department spokesman Jose Cardoza told the Los Angeles Times that they plan to expand their search to include two reservoirs located near Sierra LaMar's home after underwater searches of the Chesbro and Uvas reservoirs last week did not result in her body being found. The Calero and Anderson reservoirs will now be searched.

And on Monday authorities told local Fox affiliate KTVU-TV that crime lab tests have led to new leads, though specifics were not available at the time.

Cardoza said that shortly after Sierra LaMar went missing, her cellphone was found about 0.75 miles from her home by police who tracked it electronically; and a Juicy brand bag of hers was found a couple of miles away with pants and a shirt of hers folded inside it. He told KTVU-TV that the leads are in connection to one of those items, but declined to comment further about the details of the leads.

But Steve LaMar, Sierra's father, who is a registered sex offender but not believed to be a suspect in the case, said he hopes the leads will help authorities solve the case:

I hope something pans out, because we've just been desperate for something.

Sierra LaMar, missing now for a month and a day, was 5'2 tall with dark brown hair.

Anyone with any information about the case should call the Santa Clara County Sheriff's Department at 408-299-2311.