An employee of the Decatur Library told police she observed a man masturbating on the third floor Jan. 17.
The employee said she was working at the desk about 3 p.m. and heard the heavy breathing of a man.
She said she looked up and saw a man with his pants unzipped between the book stacks. The man got on the elevator and left the third floor.
The employee described him as black, tall with a slender build and wearing a blue baseball hat, gray fleece sweat shirt and blue jeans. He was carrying a black book bag and a black umbrella.