Polly was born in Fairfax, California to Marc Klaas and Eve Klaas. Her parents divorced when she was two-years-old. She was their only child. Polly and her mother moved around California, frequently, before moving to Petaluma, California. Eve was briefly remarried to a man named Allan Nichol. He and Eve had a daughter named Annie in 1987, giving Polly a half-sister. At twelve-years-old, Polly was abducted, at knife point, from her mother's home in Petaluma, during a slumber party. Her kidnapping received national attention. She was murdered by her abductor, Richard Allen Davis, who was convicted and sentenced to death in 1996. She was attending Petaluma Junior High at the time of her death. She played clarinet in the school band and Louisa May Alcott's "Little Women" was her favorite book.
