CALDWELL, ID – An Idaho man is in custody after authorities allege he killed his teenage daughter and assaulted his son in what police describe as a violent attack within their family home.

Delbert Cornish, 51, faces charges of first-degree murder and aggravated assault after a series of events on Monday led to the death of his 18-year-old daughter and a confrontation with his teenage son, according to court records. Cornish is being held without bond at the Canyon County Jail.

Authorities say the violence unfolded in the quiet Caldwell suburb, where Cornish allegedly consumed several shots of alcohol early in the morning before entering his daughter Hope Cornish’s bedroom and fatally shooting her. Investigators found that he had covered her body with a pride flag, a gesture he reportedly told police was meant to honor her.

The attack continued hours later when Cornish’s teenage son returned home from school, officials said. Cornish allegedly revealed to his son that he had killed his sister and tried to persuade him to check on her, but the boy refused. When the situation escalated, Cornish reportedly grabbed a handgun, blocked the doorway, and aimed the weapon at his son after firing into the floor. In the struggle that followed, the younger teen managed to seize control of the gun and flee the residence to call authorities.

Responding officers arrived at the home shortly after 4 p.m., discovering a handgun on the couch and a magazine on the floor. The scene was marked by what prosecutors called a chilling clue: a note scrawled on a wall that appeared to discuss murder and suicide, expressing hopelessness and referencing bullying toward Cornish’s children.

Investigators soon found Hope Cornish’s body inside a bedroom. Evidence indicated a violent confrontation had occurred, with a hatchet embedded in the door to her room. Cornish was not at the scene, prompting an urgent search by police.

Through license plate tracking, law enforcement located Cornish driving a vehicle in Mountain Home, nearly 50 miles away. He was apprehended without incident as he appeared headed to see an ex-girlfriend, police said.

In interviews with investigators, Cornish allegedly confessed to shooting his daughter. He also expressed remorse for his actions and reportedly told officers he suffered from alcoholism and depression. According to court documents, Cornish explained to police that he felt overwhelmed by his struggles and by alleged bullying faced by his children, circumstances he believed justified his actions.

Cornish had purportedly planned to end his own life and those of his children, telling detectives he did not believe anyone would take care of them after his death. He also cited feelings of worthlessness and tension with his brother, with whom he and his children had been living.

The accused reportedly admitted he had intended for all three of his children to be victims, but his eldest son was not present, having been incarcerated weeks earlier. After his son escaped on Monday, Cornish told detectives he attempted to take his own life but was unable to do so because the gun would not fire.

A preliminary hearing for Cornish has been scheduled for Sept. 3. Investigation remains ongoing as authorities review evidence and interview those connected to the case.

Local officials have called the incident a tragedy, emphasizing the impact on the community and the family left behind.