A man in Idaho will spend the rest of his life in prison for killing his teenage daughter and trying to kill his young son.
According to a statement from the Canyon County Prosecuting Attorney’s Office, 51-year-old Delbert Cornish was sentenced to life in prison without the possibility of parole.
He was charged with first-degree murder for killing his 18-year-old daughter and attempted murder for attacking his 15-year-old son. Cornish was also charged with animal cruelty for shooting his daughter’s pet cat.
Cornish avoided the death penalty by pleading guilty in November 2025. In exchange, prosecutors dropped that option. He admitted to first-degree murder, assault with intent to commit murder, cruelty to animals, and use of a deadly weapon in the commission of a felony, according to KTVB.
The crime happened on August 18, 2025. Court records say Cornish took several shots of alcohol before going into his daughter’s bedroom. There, he shot her in the head. The victim was identified as Hope “Onyx” Cornish.
Afterward, he kissed her on the cheek, shot her pet cat, and covered her body with a Pride flag. Investigators said this was meant to honor her, the Law & Crime reports.
After killing his daughter, Cornish waited at home for his son, 15-year-old Lucian Cornish, to return from school. When the boy arrived, Cornish told him that his sister was dead and urged him to go check on her. Lucian refused. Cornish then fired a gun into the ground. At that point, Lucian fought back, wrestled the gun away, and called 911.
Police who arrived at the home found a message written on the wall. It read, “I’m a man of my word my kids died by my hand. I’m tired of them being made fun of” and “I’m going! My kids are going with me.”
Cornish fled the scene but was arrested about 70 miles away. When officers took him into custody, he reportedly said, “I’m not gonna lie. I did it, dude.”
Investigators later learned that Cornish had bought the gun about a year earlier and had been planning to kill his children and himself during that time.
During sentencing, Idaho 6 News reports Cornish apologized in court. He told the judge, “I could never muster enough words to convey the amount of regret, anguish and remorse I have for what I’ve done… That’s a debt I could never pay back in this lifetime or the next.”
Third District Judge Gabriel McCarthy ended the hearing with strong words. “If there’s a God, perhaps God will have mercy on his soul. But the state of Idaho does not,” the prosecuting attorney’s office quoted him as saying.
Cornish will now be transferred to state prison, where he will serve his life sentence.
