Andy Stack is the pseudonym for Ann Rae Rule, an American author renowned for her true crime books and articles. She was born on October 22, 1931, in Lowell, Michigan.

Ann Rule is best known for her work The Stranger Beside Me (1980), which explores the life of serial killer Ted Bundy, whom she knew personally as a co-worker and friend before his true nature was revealed. Over her prolific career, she authored more than 30 true crime books, including Small Sacrifices, a gripping account of Oregon child murderer Diane Downs.

Many of Ann Rule's books focus on murder cases that took place in the Pacific Northwest, particularly in her adopted home state of Washington.