‘What the hell?’ Caldwell man accused of killing his 18-year-old daughter

CALDWELL (Idaho Statesman) — An Idaho man was arrested Monday night after he allegedly killed his 18-year-old daughter, leaving the victim’s mother baffled and “so angry” about the loss of her daughter.

Officers with the Caldwell Police Department responded just after 4 p.m. Monday to a home in the 1600 block of Blaine Street after Delbert Cornish’s son called 911 to report that his father was inside armed with a gun, according to a news release from the agency.

Officers said they found the son outside, and he told police that his father made comments about shooting a family member, and then attempted to prevent him from escaping. The son got out of the house unharmed after a “short struggle,” according to the release.

Police found a young woman dead inside the house and also recovered a firearm, the release said. She was identified Tuesday by the Canyon County Coroner’s Office as Hope Cornish.

To her family and friends, Hope was known as Onyx: a strong-headed young woman who loved music — particularly heavy metal — and was outspoken about her distaste for the current president of the United States, her mother said.

“She was very protective of her brothers,” Crystal Thompson told the Idaho Statesman in an in-person interview Tuesday. “She was smart, too. Beautiful.”

Thompson, who passed her musical tastes to her daughter, said some of Onyx’s favorite bands were Avenged Sevenfold and Bullet For My Valentine.

Onyx dealt with substance abuse issues, Thompson said, but had been sober for over a year, had recently started dating someone new and had a job working at the Wendy’s off of 10th Avenue in Caldwell.

“She was doing better,” Thompson said.

Onyx and her dad “always butted heads,” but Thompson said she never expected he could be violent. Onyx and her brother, Thompson’s middle child, were living primarily with the 51-year-old Cornish, she said.

“At one point in time, I loved this man,” Thompson said. “But I’m just so angry — my daughter’s dead. What the hell?”

Cornish initially fled from the scene but was apprehended at a residence in Mountain Home at around 7:30 p.m. Monday and booked into the Elmore County Jail, the release said. He was arrested on suspicion of two felony counts, first-degree murder and attempted murder, online records showed.

“My heart is heavy, and I am deeply saddened for the family and friends affected by this horrific act of family violence,” Caldwell Police Chief Rex Ingram said in the release.

Thompson’s youngest son, who lives with her, still doesn’t know about his sister’s death, Thompson said. She told the Statesman on Tuesday that she’s trying to figure out the best way to tell him because he has autism and isn’t going to understand.

Thompson said she would work over the next few days to organize a celebration of life for Onyx.