Robert John Bardo was born on January 2, 1970, at Edwards Air Force Base in California. He was the youngest of seven children. His mother was Japanese, and his father, Philip, served as a non-commissioned officer in the United States Air Force. Because of his father's job, the family moved around often. In 1983, they settled in Tucson, Arizona.

Bardo had a troubled childhood. He was reportedly abused by one of his siblings, which affected him deeply. His struggles led to a serious incident where he threatened to commit suicide. As a result, he was placed in foster care for a period of time. The family also had a history of mental illness. Bardo himself was later diagnosed with bipolar disorder.

At the age of 15, Bardo was institutionalized for a month to help him work through his emotional problems. His education did not go smoothly. He dropped out of Pueblo Magnet High School in the ninth grade. After leaving school, he found a job as a janitor at Jack in the Box.

Robert John Bardo became obsessed with actress Rebecca Schaeffer after previously stalking Samantha Smith, a child peace activist. He sent numerous letters to Schaeffer and tried to enter the set of the TV show "My Sister Sam," where she starred. When security turned him away, he left calmly, which made the incident seem less serious. Eventually, he hired a detective agency to find Schaeffer’s home address through the Department of Motor Vehicles.

On July 18, 1989, Bardo went to Schaeffer's apartment. He was angry because he felt she had "lost her innocence" by appearing in a sex scene in a movie. After being turned away at her door, he left but returned an hour later. When Schaeffer opened the door again, Bardo shot her in the chest. Following the shooting, he was seen wandering in traffic in Tucson, Arizona, where he was arrested.

During his trial, Bardo's defense acknowledged that he killed Schaeffer but claimed he was mentally ill. A psychiatrist testified that he had schizophrenia, which influenced his actions. Bardo was found guilty of first-degree murder and received a life sentence without the possibility of parole.

As he fled from the crime scene, Bardo discarded a red copy of "The Catcher in the Rye," which he later claimed was just a coincidence. During his time in prison, he was attacked by another inmate, suffering multiple stab wounds. Bardo continues to serve his life sentence at Avenal State Prison, California. His actions led to changes in laws regarding stalking and privacy, including the Driver's Privacy Protection Act.