search there are new developments in the investigation. bring sierra home. reporter: 500 balloons were released as symbols of home, each containing a message. the anxiety and fear of where she is and what has happened to her is unbearable. reporter: sierra s parents say they gather strength from friend and volunteers who conducted numerous searches. if sierra could be here right now she would say, thank you for not giving up on me. reporter: the 15-year-old went missing a month ago, possibly when she was walking to a bus stop to go to school. test results from the crime lab has yielded new leads but they did not release details. it is one of those items, we can t specify as to this point as the results back from the cell phone, the results back from the clothing. from sierra s clothing or a couple of the other evidence items that were found in this case. reporter: sierra s father told us they are waiting to hear more from investigators. i hope something pans