Diane drove to McKenzie-Willamette Hospital with her three children Stephen Daniel, Cheryl Lynn, and Christie Ann in the backseat where the entire car was blood-spattered. There was no blood on Diane. When she got to the hospital Cheryl was already dead, Danny was paralyzed from the waist down, and Christie was suffering from a stroke. Diane had been shot in the left forearm. She claimed that she had been carjacked on a rural road near Springfield, Oregon by a strange man who then shot her and her three children.
The police were suspicious because she was too calm for a person who had experienced a traumatic event. She had also made a number of inappropriate statements. They were really thrown off when upon her arrival to the hospital she had called Robert Knickerbocker, a man with whom she had been having an affair with.
Her statement to the cops didn’t fit the evidence that they had found. There wasn’t any blood on her side of the car, and there wasn’t any gunpowder residue on the driver’s side door or the interior door panel. Knickerbocker had told the police that Diane had stalked him and she had seemed willing to kill his wife so that she could have him to herself. She didn’t tell the police that she owned a .22 caliber handgun (the type of gun that killed Cheryl and harmed the other two children) but her ex-husband and Knickerbocker both said she owned one. They were never able to find the weapon, but they found un-fired casings in her home. Witnesses say that they saw her car driving at incredibly slow speeds, when she had told the police that she drove at incredibly high speeds.
She was arrested on February 28, 1984, nine months after the incident and charged with one count of murder and two counts each of attempted murder and criminal assault. Prosecutors argued that she shot her children to be free of them so that she could finally be with Robert Knickerbocker, who, she claimed, said he didn’t want children.
Her surviving daugher, Christie, testified against her once she regained the ability to speak. She told them of how her mother parked on the side of the road and shot all three children and then shot herself in the arm.
The surviving children Christie and Danny went to live with the prosecutor of the case, Fred Hugi. He and his wife adopted them in 1986.
Before her arrest and trial Diane got pregnant with her fourth child and gave birth a month after her trial to a girl named Amy Elizabeth. The baby was seized by the state of Oregon and adopted soon after; she was renamed Rebecca “Becky” Babcock. She spoke with 20/20 and Oprah about her biological mother.
Downs will have to wait until 2020 to be able to apply for parole.
Ann Rule wrote about her in Small Sacrifices.