The King County Sheriff's Office has arrested two people in connection with the murder of Denise Grigsby.
The two people - a man and a woman - are persons of interest in the case.
According to court records, both have extensive criminal backgrounds.
Grigsby's body was found in the trunk of a burning car on Auburn-Black Diamond Road last Sunday. The 39-year-old woman had been placed in the trunk after she died from a blow to the head.
The Sheriff's Department says the investigation is continuing. Detectives are asking the public for help in the case.