An Idaho community is reeling after 18-year-old Hope “Onyx” Cornish was fatally shot in her own home this week, allegedly by her adoptive father, who later told police he had planned to kill himself and his children.
Caldwell police said officers were called to a home on Tuesday, Aug. 19, after reports of an armed man inside. When they arrived, they discovered Onyx dead in her bedroom. The Canyon County Coroner’s Office later identified her and confirmed she had died from a gunshot wound to the head.
Police identified the suspect as 51-year-old Delbert Cornish. According to a probable cause affidavit reviewed by local outlets, Delbert admitted to shooting Onyx as she unexpectedly opened her bedroom door that morning. He told investigators he had been planning for months to kill himself and his three children, a plan delayed when his eldest child was sent back to prison for violating parole.
Delbert allegedly claimed that the family had endured constant verbal abuse from his brother, with whom they were living, and that the bullying left him feeling desperate. In his account to police, he said he was startled when Onyx opened her door, and he shot her before sitting in the room for nearly 20 minutes while she gasped for breath. He said he then draped her body in a Pride flag because he knew it would have been meaningful to her.
Onyx’s mother, Crystal Thompson, said she never believed her children were unsafe in Delbert’s presence. “She was a fiery one,” Thompson told News 19. “She was just very stylish, and she was kind and loving.”
Authorities said Delbert fled the Caldwell home after the shooting but was arrested later that evening in Mountain Home, about 50 miles away. He has since been charged with murder and aggravated assault. Online court records did not yet indicate whether he has entered a plea.
Family members described Onyx as a vibrant teenager with a strong sense of identity, and they recently set up a GoFundMe page to try and cover some of her funeral expenses.
What remains most unsettling, beyond the violent details of the crime itself, is the chilling mix of confession and justification offered by her father. In the affidavit, Delbert described years of planning and a twisted reasoning for wrapping his daughter in a symbol of acceptance and pride only after taking her life.
For Thompson and those who loved Onyx, that explanation does little to ease the loss. “She was just very stylish, and she was kind and loving,” her mother repeated. “She was ours.”
