Investigators with the santa clara county sheriff’s office are trying to determine who is responsible for posting a fake message online Monday night claiming to be missing morgan hill teenager sierra lamar. The message was posted on facebook. The person claimed to be the missing 15-year-old, and said she was in danger at an address in Saratoga. Authorities investigated, but the address was a vacant lot. the message is believed to have been posted by someone that hacked into lamar’s facebook account. santa clara county sheriff’s deputies are working with members of the district attorney’s rapid enforcement allied computer team to try to identify the hacker. Lamar went missing in march. She is presumed dead by authorities. 21-year-old antolin torres-garcia has been charged with her murder. he is set to return to court july 10th.