Vermont police are investigating the theft of a gold medallion bearing an image of poet Robert Frost. Police said the theft was reported Saturday afternoon at the Robert Frost Stone House Museum in Shaftsbury. Frost lived in the house from 1920 to 1929. Authorities say the small medallion, about 1 inch in diameter, was taken from a display case at the museum, but it is unclear when the theft took place. The medallion, which has been at the museum since 2003, was the only item taken. Police did not put a value on the medallion.