WINONA, Minn. – Elderly folks are being preyed upon by the Grandparent Scam. Beware, Sheriff Ron Ganrude said in an online alert.  The scam works this way: The caller claims to be a grandchild in trouble, like in a hospital or jail, and needing money. Not knowing the name of the grandchild, the caller will try to get their target to name the grandchild.