King County Prosecutor Dan Satterberg announced today the filing of six counts of aggravated murder in the first degree against Michele Anderson and her boyfriend Joseph McEnroe who are accused of murdering six members of Anderson's family in Carnation on Christmas Eve.

Anderson and McEnroe are accused in the murder of her mother and father, Judy and Wayne Anderson. They are also accused of murdering Michele's brother Scott Anderson and his wife Erica and their children Olivia, 6, and Nathan, 3. All six died from gunshot wounds.

Michele Anderson and Joseph McEnroe, both 29, lived in a mobile home located on the property. Prosecutors allege that there had been tension between Michele and her parents for years and that she was angry at her father Wayne for lack of financial support and her belief that he favored Scott. She also believed that her brother owed her money.

In filing today's murder charges, prosecutors allege the existence of two aggravating factors: That the murders were carried out as a part of a common scheme or plan or the result of a single act; and/or that the murders were committed to conceal the commission of a crime or to protect or conceal the identity of the person committing the crime.

Prosecutors accuse each of the defendants of being armed with a handgun when they entered the Anderson residence. Michele wrapped her gun in a sweatshirt. She fired once at her father and then McEnroe shot him in the head. After hearing shots, Judy ran from the back room where she had been wrapping gifts. Prosecutors allege that McEnroe then shot her in the head. They dragged the bodies of Judy, 61, and Wayne, 60, outside to a shed.

When Scott, Erica and their children arrived about an hour later for a Christmas Eve celebration, Michele confronted her brother who was then shot by both defendants. According to court documents, each defendant is accused of shooting Erica and then McEnroe shot the two children.

"In the span of one hour, the defendants had turned the Christmas Eve celebration into a scene of mass murder," Satterberg said.

If convicted as charged, the defendants would face a sentence of either the death penalty or life in prison without release. Under state law, Satterberg will have 30 days from the time of arraignment to decide whether to file a notice of intent to seek the death penalty.

Anderson and McEnroe are being held without bail in the King County Jail. Arraignment is scheduled for January 9 at the King County Courthouse.