Neighbors of Sierra Newbold say they plan to hold the vigil Friday evening at West Jordan Elementary, where she was to attend school in the fall.
West Jordan police remain tight-lipped as they investigate Newbold's death.
Reed Newbold, the girl's grandfather, said her mother found her missing from her bedroom early Tuesday. Her body was found in a canal near her home. Police say she had been sexually assaulted.
Authorities have not said whether there is evidence that the girl was taken from her home, but they are warning parents to take precautions to keep their children safe.
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