Caldwell, ID – A 51-year-old Idaho man accused of killing his adopted daughter and wrapping her body in a Pride flag is preparing to plead guilty, his attorney told a Canyon County judge this week. Delbert Cornish faces a charge of first-degree murder for the August 2024 death of his daughter, 18-year-old Hope “Onyx” Cornish, in what authorities called a “horrific act of family violence.”
The Incident: A Shocking Act of Violence Inside a Caldwell Home
According to court documents, the incident occurred on August 18, 2024, at a home on the 1600 block of Blaine Street in Caldwell, a suburb of Boise. Authorities say Cornish had been drinking that morning when he entered his daughter’s bedroom around 9 a.m. and shot her in the side of the head.
After the shooting, Cornish allegedly kissed his daughter on the cheek and then shot her pet cat, telling investigators he did it “because no one would take care of it after they were all dead.”
“He then covered Hope’s body with a large Pride flag,” investigators wrote in the probable cause affidavit, “as a way to honor her because it was something that meant a lot to her.”
Police said the crime scene also included a murder-suicide note written on the wall, where Cornish allegedly wrote: “I’m a man of my word. My kids died by my hand. I’m tired of them being made fun of.”
Investigation and Evidence
According to the Green County District Attorney’s Office, the evidence shows that Cornish had been planning the murder for nearly a year. He purchased a black 9 mm Hi-Point handgun in September or October 2024 and told police he intended to kill his three children and himself.
After shooting Hope, Cornish allegedly waited for his 14-year-old son, Lucian, to return home from school. When Lucian arrived, Cornish told him, “I killed your sister,” and tried to convince him to go check her body. The teen refused, and Cornish pointed a gun at his chest before firing a shot into the ground.
“Lucian fought for the weapon and managed to grab it before running away to call 911,” the affidavit said.
When law enforcement arrived around 4 p.m., they found Hope Cornish dead, her cat beside her, and a note that appeared to describe Cornish’s intentions to end his own life. He was later arrested about 70 miles southeast of the home, reportedly heading to his ex-girlfriend’s house.
During questioning, Cornish confessed to the murder and “began to cry” when told that his daughter’s body had been found. He allegedly told officers, “I’m not gonna lie, I did it, dude.”
Court Proceedings and Plea Announcement
Cornish was charged with first-degree murder, assault with intent to commit murder, and animal cruelty. The initial charge of aggravated assault was upgraded after investigators uncovered evidence that Cornish also threatened his son with the same firearm used to kill Hope.
On Tuesday, Cornish appeared before a Canyon County judge with a shaved head, where his attorney announced the intent to change his plea to guilty. The court scheduled a change-of-plea hearing for November 12, 2025, though it remains unclear whether the plea is part of a deal with prosecutors.
Reactions from the Family
In an emotional interview with local media, Crystal Thompson, Hope’s mother and Cornish’s former partner, described the pain of seeing him in court.
“You hear people say, ‘my blood went cold.’ That’s what happened to me,” Thompson said. “I started shaking and just felt despair.”
She added that Cornish made brief eye contact before looking away.
“He’s going to have to face it,” she said. “And it’s not fair.”
Hope’s brother, Lucian, has remained by his mother’s side throughout the legal process as they seek justice for Hope’s death and prepare to attend the sentencing hearing.
Background and Motive
The court documents revealed that Cornish admitted to being an alcoholic who struggled with depression. He reportedly told investigators that he intended to kill his children and himself because he believed “no one would take care of them after he was gone.”
Police believe that the Pride flag wrapped around Hope’s body was symbolic — representing something she cared deeply about, as she identified within the LGBTQ+ community.
The tragic combination of mental illness, substance abuse, and premeditation paints a disturbing picture of a man who methodically planned his actions over the course of nearly a year.
Ongoing Developments and What Comes Next
As the case moves forward, Cornish’s formal guilty plea is expected at the November hearing. Prosecutors have not yet announced whether they will seek life imprisonment or a possible plea agreement.
The case has drawn national attention due to its connection to LGBTQ+ identity and the symbolism of the Pride flag, raising conversations about mental health awareness and family violence prevention.
Authorities have since called the killing “a heartbreaking reminder of the dangers of untreated depression and access to firearms.”
Conclusion
As Delbert Cornish prepares to enter his guilty plea, Hope “Onyx” Cornish’s family continues to mourn the loss of a daughter remembered for her kindness and self-expression. The sentencing will determine whether her father spends the rest of his life in prison for the crime that shattered their family.
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