The disclosure came as a local judge ordered the suspect in the case, John Robert Charlton, held on $US2 million ($A2.60 million) bail.
Charlton has a criminal history. His parents had sought a restraining order against him in 2006, saying he had taken the movie Hannibal - about a serial killer - from a shelf and told his mother she should watch it and "beware".
Charlton, 37, was arrested Monday after police said remains believed to be those of Ingrid Lyne of Renton were found over the weekend in a homeowner's recycling bin. A head, arm with a hand, lower leg and foot were recovered, court documents state.
Lyne, 40, was reported missing on Saturday. The coroner's office was working to confirm the remains were hers.
Her family released a statement on Tuesday, saying they are heartbroken.
"This weekend, a light went out of our lives forever. Ingrid, beloved mother, daughter, sister, and friend was taken from us for reasons we still cannot comprehend," the statement said.
Lyne had planned to go on a date to a baseball game Friday night, friends said. A neighbour told detectives she had been dating a man named John.
Charlton told police he went to the baseball game with Lyne and returned to her home that night but was so intoxicated he couldn't recall what happened. He said he had been dating Lyne for about a month.
Seattle police detectives searched Lyne's suburban home Sunday and found a 15-inch pruning saw near the bathtub, an empty box of plastic garbage bags identical to the type containing the body parts, and collected swabs of suspected blood, according to court documents.
Police said Charlton had abrasions on his forehead and hand, injuries to his lip and chin, and scratches on his chest.
Charlton told police he spent Saturday and Sunday night at the Lake Stevens, Washington, home of a former girlfriend
Originally published as US woman dismembered in home, parts dumped