Deputies received a 911 call reporting the shooting around 3 a.m., said Sgt. Cindi West with the King County Sheriff's Office.
When deputies arrived at the home in the 6200 block of S. 117th Place, they found three men and a woman had been shot.
All four were rushed to Harborview Medical Center in Seattle, where two victims are said to be in critical condition.
Witnesses said several people at the party were armed and had a "show and tell" with their guns," said Sgt. Cindi West with the King County Sheriff's Office. Just before 3:00 am an argument started over a gun. A shootout ensued during the argument which resulted in four people being shot.
West said it's not knwown how many people were shooting and who had initiated the shooting. Detectives have not been able to interview victims due to their injuries.
Investigators determined that three people fled the scene prior to the arrival of police. Detectives located two of the people and were working with the family of the third to convince him to come to the police to tell his side of the story.
But then later Sunday evening, detectives learned that the third man is Benjamin C. Barnes, who became a person of interest in a fatal shooting of a park ranger in Mt. Rainier National Park later Sunday morning.