Beverly Police said an armed robbery was reported at Rite Aid on Cabot Street around 8:20 p.m. Monday night.
Police spokesman Dave Costa said the alleged robber was described as 'white male, slim build, possibly 5'8" or 5'9", wearing dark colored hooded sweatshirt, dark navy jeans, and a white ski mask'.
The man was carrying a knife having an estimated 12-inch blade.
Costa said the alleged robber "walked in, did a quick walk through the store, then walked behind the front counter and demanded that the clerk open the registers and give him the money."
The clerk gave him money from two registers, estimated to be about $538.
The robber then reportedly said, "Have a nice night ma'am." and left the store.