When police entered a Caldwell, Idaho, home on August 19, they found a horrifying scene: 18-year-old Hope “Onyx” Cornish was dead, her body draped in a Pride flag. Hours later, authorities said, her father confessed to the killing, and explained why he did it.The suspect, 51-year-old Delbert Cornish, was arrested that evening in Mountain Home after fleeing the scene. According to a probable cause affidavit reviewed by Idaho News 6 and PEOPLE, Delbert admitted he shot his daughter in the head inside the family’s home.Investigators say Delbert told them he had been planning since last year to kill himself and his three children. The plan, he claimed, unraveled after his eldest child was sent back to prison on a parole violation.Delbert also alleged that his brother, who lived in the same house, constantly bullied the children with insults like “loser” and “pedophile.” On the morning of the killing, Delbert said he walked to Onyx’s room and was startled when she opened the door. He then pulled the trigger.According to the affidavit, Delbert watched for nearly 20 minutes as his daughter gasped for breath before dying. Only after that, he told police, did he cover her body with a Pride flag, saying it was meant to “honor her” because it would have been deeply meaningful to her.The Canyon County Coroner’s Office later identified the victim as Hope “Onyx” Cornish. Her mother, Crystal Thompson, told News 19 she never imagined her children weren’t safe around Delbert. “She was a fiery one. She was just very stylish, and she was kind and loving,” she said.A GoFundMe set up by the family describes Onyx as a lively spirit whose memory continues to be celebrated.