CANYON COUNTY, Idaho — A Caldwell father charged with killing his daughter in August formally pleaded guilty to first-degree murder in a Canyon County courtroom Wednesday, emotionally admitting to the crimes in front of a judge.
Delbert Cornish told the court he shot his daughter, Onyx Cornish, killed her cat, and threatened his son, who survived the ordeal.
In court, Cornish told the judge, "I pulled the trigger. I shot my daughter."
The judge then asked, "You shot your daughter with a 9-millimeter firearm. Did you know what you were doing when you pulled the trigger?"
Cornish responded, "Yes."
RELATED | Onyx Cornish’s mom remembers her daughter’s kindness and close bond with family
He also admitted to threatening his son while still armed, saying, "I attempted to do the same to my son."
Cornish now awaits sentencing.
Onyx’s mother, Crystal Thompson, described the hearing as overwhelmingly painful. "That was hard. That answer was really— I don't know. It's like a truck hit me, just to hear him say it. It's made it all the more real, and I'm really struggling right now with that."
Despite the trauma, Thompson said her son, Lucian Cornish, is channeling his emotions into music.
RELATED | Caldwell teen recounts the day his sister Onyx was killed
"He wrote a song, actually, and he's writing an album, and he's doing all these musical things to get out his emotion," added Thompson. "It's really, really cool. It's really great. It's hard to hear, of course, because it's so emotionally raw."
Lucian is preparing to give a victim statement at sentencing.
Delbert Cornish is expected back in court for sentencing on January 28, when Lucian will provide his statement.
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