A Carnation woman and her former boyfriend could face the death penalty for the Christmas Eve slayings of six members of her family.

For months, Michele Anderson has insisted that she deserves to be executed for killing six members of her family during a Christmas Eve gathering in Carnation.

“I want the most severe punishment, which would be the death penalty,” Anderson told The Times during a jailhouse interview in June. “I think if I kill a bunch of people, I’m not sure I deserve to live … I want to waive my trial.”

But after King County Prosecutor Dan Satterberg announced Thursday that he would ask jurors to consider the death penalty for Anderson, 30, and her former live-in boyfriend Joseph McEnroe, 29, her attorney says they will mount a vigorous defense to keep her from becoming the first woman to be executed in Washington state.

“Now that the prosecutor has decided to seek the death sentence, Ms. Anderson and her defense team will fight to save her life,” said defense attorney Stephan R. Illa.

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Illa acknowledged that Anderson has told the media she was guilty, but he said that Anderson changed her mind about being executed after he and attorney Lisa Mulligan took over her case in August. Anderson fought with her previous defense team and even prevented them from presenting evidence to Satterberg on her behalf, he said.

Illa and Kathryn Ross, who is representing McEnroe, said they believe that “mitigating evidence” will keep jurors from sending their clients to death row. Neither would elaborate.

On Thursday, Satterberg said both Anderson and McEnroe are deserving of capital punishment because they killed three generations of her family, including two young children.

Anderson and McEnroe are accused of fatally shooting Anderson’s parents, Wayne and Judy Anderson; Anderson’s brother and sister-in-law, Scott and Erica Anderson, both 32; and the couple’s children, 5-year-old Olivia and 3-year-old Nathan.

“The death penalty is this state’s ultimate punishment and is to be reserved for our most serious crimes,” Satterberg wrote in a statement. “I believe this is one of those crimes.”

Several relatives of the victims attended a brief hearing Thursday during which Senior Deputy Prosecutor James Konat filed a notice of intent to seek the death penalty against both defendants. Neither Anderson nor McEnroe attended the hearing.

Pam Mantle, mother of victim Erica Anderson, said that her daughter would have wanted to see the defendants face a death sentence.

If found guilty, Anderson and McEnroe face only two possible sentences for the six counts of aggravated murder they each face: execution or life in prison without the possibility of parole.

Satterberg’s decision ends months of speculation over whether he would seek to have the pair executed for what many consider to be among the most heinous crimes in King County history. The victims were all gunned down in the rural Carnation home of Michele Anderson’s parents as they were preparing for a Christmas Eve gathering.

Anderson told The Times during her jailhouse interview on June 27 that the pair killed her family in a fit of rage, claiming she had suffered years of physical and emotional abuse.

Anderson’s confession and insistence that she wanted to plead guilty had been moot until Satterberg’s decision. State law prevents a defendant from entering a plea other than not guilty in a death-penalty case before a decision on execution is made.

This is the first time that Satterberg has weighed the death penalty since taking over as prosecutor after the death of Norm Maleng in May 2007. Satterberg, who was named interim prosecutor after Maleng’s death, was elected to the position last November.

It’s also only the second time King County has pursued the death penalty since Maleng sought it for Green River killer Gary L. Ridgway, whose case has become a litmus test of sorts with regard to the death penalty in Washington state.

Prosecutors eventually opted against capital punishment in exchange for Ridgway’s cooperation, during which he provided detectives details that helped solve dozens of open murder cases. Ridgway pleaded guilty to 48 counts of aggravated first-degree murder in 2003 and was sentenced to life in prison without possibility of parole.

Some defense attorneys and death-penalty opponents have argued that since Ridgway was sentenced to life, how can the state seek the death penalty against defendants accused of killing fewer victims.

James Conroy, the attorney for Conner Schierman, who also faces a potential death sentence in King County, has argued that it is unfair for his client to face the execution when Ridgway did not. Schierman, 27, is accused of killing his Kirkland neighbor Olga Milkin, 28; her sister Lyubov Botvina, 24; and Milkin’s two sons, Justin, 5, and Andrew, 3, on July 17, 2006, and setting fire to their home.

But in 2006, the state Supreme Court ruled that Dayva Cross, who killed his wife and two of her daughters in Snoqualmie in 1999, should not be spared the death penalty because of the Ridgway case. In the 5-4 decision, the majority ruled that the Legislature was the appropriate body to sort through the moral question of fairness with respect to other cases.

The U.S. Supreme Court has refused to hear Cross’ case.

State Rep. Brendan Williams, D-Olympia, says the issue of how the death penalty is applied needs to be reviewed by the Legislature. He sponsored a bill last year that would have created a bipartisan task force to review the death-penalty statute and determine the uniformity of decision-making by prosecutors in aggravated-murder cases. He said the bill died before making it out of the House.

“There is a randomness in how the death penalty is applied in our state. If you hide the bodies, like in the Green River case, you’ll get cut some kind of deal. If you burn a house down and all the bodies are found you will get charged with the death penalty,” Williams said.

Williams said he hopes to revive a similar bill in the coming legislative session.

But convincing a jury to impose the death penalty post-Ridgway may not be the toughest issue Satterberg will face.

Of the 77 inmates Washington state has executed since 1904, all have been men. In more than a quarter-century, Washington prosecutors have only sought to execute two women.

The most recent was in 2003 in Snohomish County, where jurors decided against execution and instead sentenced Barbara Opel to life in prison without parole for persuading five teens, including her 13-year-old daughter, to fatally beat Jerry Heimann of Everett.

Seattle attorney Jeff Ellis, president of the Washington Coalition to Abolish the Death Penalty, said he had hoped that Satterberg would not seek the death penalty.

“We are profoundly disappointed in prosecutor Satterberg’s decision. It was our hope we would not see the death penalty anymore in King County,” said Ellis, who handles death-penalty cases across the country. “The death penalty constitutes throwing a lot of money at something I think is immoral.”

Jennifer Sullivan: 206-464-8294 or jensullivan@seattletimes.com

Information from Seattle Times archives is included in this report.