NEW : ` ` I ca n't imagine a parent doing this to a child , '' Sandra Cantu 's aunt says . NEW : Police said Huckaby lives in the same mobile home complex where Sandra lived with her family ; the Tracy Press reported Huckaby lives with her grandparents . Suspect 's mother was Sandra 's friend , playmate . Melissa Huckaby was arrested on charges of kidnapping and murder , police say . Body of Sandra , 8 , was found Monday morning in a bag submerged in a pond .
NEW : ` ` I ca n't imagine a parent doing this to a child , '' Sandra Cantu 's aunt says . NEW : Suspect 's mother was Sandra 's friend , playmate . Melissa Huckaby was arrested on charges of kidnapping and murder , police say . Body of Sandra , 8 , was found Monday morning in a bag submerged in a pond .