Robert Wayne Danielson Jr. was born on August 25, 1946, in Iowa. Not much is known about his early childhood. However, it was revealed later that he experienced depression and struggled with drug use as he grew up.

In the years leading up to his adult life, Danielson faced challenges that shaped his future. He went through various personal issues, but the details of his youth remain largely unreported. As an adult, Danielson committed serious crimes and underwent a significant change in his beliefs while in prison.

On June 23, 1970, Robert Wayne Danielson shot and killed Thomas Elroy Davis during an argument by the roadside near Marcola, Oregon. Although Danielson faced a first-degree murder charge, the case ended in a mistrial due to improper evidence. In November 1970, he pleaded guilty to voluntary manslaughter and received a 25-year prison sentence.

After serving eleven years, Danielson was paroled in November 1981. On December 9, 1981, he confronted Harold and Betty Pratt at a campsite in Arizona. He tied their hands and shot them both in the head before stealing their pickup truck. Their bodies were found the next day, and a reward was offered for information.

While living in Springfield, Oregon, Danielson entered a relationship with 14-year-old Lenora Hart Johnson. On June 21, 1982, Danielson and Johnson attacked 62-year-old Arthur E. Gray in a park. Danielson bound Gray and shot him in the back of the head. His body was discovered several days later.

In July 1982, Danielson and Johnson encountered 69-year-old Benjamin and 62-year-old Edith Shaffer in a park in California. Johnson bound the couple's hands with twine, and Danielson shot them after sending Johnson away with their dog. In November of the same year, Danielson killed 38-year-old Ernest Corral in a similar manner in Apache Junction, Arizona.

Detectives began investigating after the bodies of the Shaffers were found in December 1983. Danielson was identified as a suspect because he used the couple's credit cards. Johnson later confessed to being involved in the murders and provided information about the others. Danielson was charged with two counts of murder but fled. He was apprehended on April 6, 1984, in Odessa, Texas.

During his trial for the murders of the Shaffers, his mother tried to pass him a loaded gun in court. In July 1986, he was found guilty of their murders and sentenced to death. Danielson requested leniency, reflecting on his actions during testimony. Two months later, the jury imposed the death penalty.

Danielson was sent back to Oregon to face charges for the murder of Arthur Gray. In February 1987, he was found guilty and sentenced to life in prison because the death penalty was not applicable based on the timing of the crime.

Danielson spent his remaining years on death row at San Quentin State Prison. On September 7, 1995, he was found hanging in his cell, and prison officials declared him dead.