Dean Holmes pleaded guilty to two counts of aggravated first degree murder last week, leaving a judge the only choice of sentencing Holmes to life in prison without possibility of parole or the death penalty.
Prosecutors say they will ask Holmes receive two life sentences without the possibility of parole.
"Dean Holmes will be spending the rest of his life in prison with no chance of parole," Prosecutor Mark Lindquist said in a statement released to the media. "I made this decision after consultation with leaders in the office. We took into account the severity of his crimes, his remorse as demonstrated by his surrender to law enforcement and expeditious plea of guilty, his lack of felony criminal history, the likelihood of the death penalty being upheld, and other factors."
He added he spoke with the family members of the victims and they were supportive of his decision.
"Balancing all considerations, I believe justice is achieved by two life sentences without the possibility of parole," Lindquist said.
The body of Holmes' wife Kristi and his daughter Violet were discovered in late August after Holmes walked into the Pierce County Jail early one morning and said he fatally shot his wife and child.
Prosecutors say Dean Holmes pulled a revolver from a dresser early the morning before and shot his wife of 12 years four times as she was sleeping in their bed. Violet was sleeping with a friend in the living room and didn't hear the gunshots due to the sound of a fan running nearby.
After the shooting, Holmes reloaded, then woke the girls and drove them to drop the friend off at her home in Auburn.
On his way home, Holmes pulled over and shot his daughter several times as she lay sleeping in the backseat. He then drove to a fast food restaurant, and ordered food through the drive-thru with his dead daughter in the backseat.
He returned home and put Violet's body next to his wife's then got back in the car and drove around aimlessly, prosecutors said. He decided the next morning to turn himself in.
Holmes will be officially sentenced on Dec. 7.