The woman died of her injuries within hours of the shooting, but her brother is still clinging to life.
"I just committed a father's worst sin," Michael League tells a dispatcher in a recording of his call to 911. "I just shot my daughter in the head, and my son in the head."
Speaking slowly with deep breaths, League told the dispatcher his son was on a living room couch while his daughter was in an upstairs bedroom.
"I put them out of their misery," League said.
On the 911 call, League, 69, began sobbing as he spoke of how he and his wife came home Friday to discover his son and daughter had a violent fight that required police intervention.
"It's all because of alcohol and drugs. It tore this family," he told the dispatcher.
League said five times during the call that he wanted to take his own life.
"I can't take this anymore," he said at one point. But the dispatcher pleaded with League to set the gun down. About 10 minutes into the call the dispatcher convinced League to surrender to officers who were waiting outside his house.
In Pierce County Superior Court on Monday, League was in a wheelchair and sounded distraught at times as he pleaded not guilty to charges of first-degree murder and first-degree attempted murder. His bail was set at $2 million.
The two victims were identified by family members as Dennis League, 46, and Danielle Faucett, 43.
Michael League's wife and two grandchildren were in the home at the time of the shooting but were not hurt.