Idaho Father Who Killed Daughter and Wrapped Pride Flag Around Her Body Set to Plead Guilty, Lawyer Says
CALDWELL, IDAHO — A 51-year-old Idaho man accused of killing his daughter and covering her body with a pride flag told the court through his lawyer this week that he plans to plead guilty to murder charges.
Delbert Cornish was charged with first-degree murder in the August death of his 18-year-old daughter, Hope “Onyx” Cornish, at their home in Caldwell, a suburb of Boise. Authorities said he also shot the family’s cat and left behind a chilling note describing his intent to kill his children and himself.
‘My Blood Went Cold,’ Says Victim’s Mother
Cornish appeared in Canyon County Court on Tuesday with a shaved head, where his attorney announced the plan to change his plea.
“You hear people say, ‘my blood went cold.’ That’s what happened to me,” said Crystal Thompson, Hope’s mother, speaking to KIVI-TV. “I started shaking. I felt despair.”
Thompson, who previously dated Cornish, said he made brief eye contact with her in court but quickly looked away. “He’s going to have to face it,” she said. “And it’s not fair.”
The August Morning of the Murder
According to court documents, Cornish began drinking early on August 18, taking several shots of alcohol before entering his daughter’s bedroom around 9 a.m. and shooting her in the head.
Police said he then kissed her on the cheek and covered her with a large pride flag, saying it was “something that meant a lot to her.”
Cornish also shot her cat, telling police he did so “for the same reason, because no one would take care of it after they were all dead.”
Murder-Suicide Plan Revealed
Investigators later discovered Cornish had been planning a murder-suicide for nearly a year, ever since buying a handgun in late 2024.
After shooting his daughter, Cornish allegedly waited for his 14-year-old son, Lucian, to return from school. When Lucian arrived, his father calmly told him that he had killed his sister.
“Delbert then went to the couch and grabbed a gun,” the affidavit states. “He blocked the doorway and pointed the gun at his son’s chest.”
Lucian fought back, managed to wrestle the gun away, and ran to call 911.
Crime Scene and Chilling Message
When police arrived that afternoon, they found Hope Cornish and her cat dead in the bedroom. A large note scrawled on a wall appeared to be Cornish’s intended suicide message, saying:
“I’m a man of my word. My kids died by my hand. I’m tired of them being made fun of.”
Investigators arrested Cornish about 70 miles away, near his ex-girlfriend’s home, after tracking his vehicle.
He confessed to the killing, telling officers, “I’m not gonna lie, I did it, dude,” and began to cry when told police had found his daughter’s body.
Motive: ‘He Thought They Couldn’t Live Without Him’
Court records indicate Cornish struggled with alcoholism and depression and told detectives he believed his children “could not carry on without him.”
“Delbert explained he wanted to kill his children along with himself because he believed nobody would take care of them once he was dead,” the affidavit states.
A change-of-plea hearing is set for November 12, where he is expected to formally enter a guilty plea.
Hope’s brother Lucian has remained by his mother’s side as they continue to pursue justice for Hope “Onyx” Cornish, who friends described as bright, compassionate, and fiercely authentic.