Mistrial declared in case of Altoona woman who claims self defense in boyfriend's killing

A Polk County judge has declared a mistrial in the case of a woman who says she believed her boyfriend was going to attack her before she shot and killed him.

Marique Ruth, 44, is charged with first-degree murder in the August 2022 death of 41-year-old John Killen. The shooting took place in their shared Altoona home.

Ruth told detectives Killen was drunk and that she believed he was about to attack her before she shot him at least three times.

The case went to trial May 13. On May 16, however, the court declared a mistrial after jurors were shown statements on video they were not supposed to have seen.

Assistant Attorney General Scott Brown confirmed the mistrial was related to a video recording of an interview between Ruth and an Altoona police detective, and that due to an oversight two particular statements Ruth made were not edited out before it was shown to the jury. The Iowa Attorney General's Office is prosecuting the case due to a reported conflict of interest for the Polk County Attorney's Office.

Andrew Petrovich, one of Ruth's attorneys, said in an email that it's unfortunate the trial will have to be rescheduled. Judge Celene Gogerty has set a May 23 hearing to select a new date.

"Although we feel that the court made the correct decision regarding our motion for a mistrial, we are disappointed that justice for Ms. Ruth had to be delayed," Petrovich said.

Who was afraid of whom before fatal shooting?

Prior to the mistrial, the jury heard arguments and testimony about whether Ruth had a legitimate reason to fear for her safety before shooting Killen.

Defense attorney Joseph Leichty argued in his opening statement that the two were in a "toxic" relationship marked by aggression and belligerence from Killen.

"John had a drinking problem, he had mental health issues, he yelled, he ran his mouth, the two argued frequently," Leichty said. "August 10 wasn’t the first time police were called out."

Related: Suspect in girlfriend's killing has history of abuse against victim

Worse, he said, Ruth knew Killen had been accused of choking another woman months before, and it had been only a short time since Killen threatened Ruth, as well. When Killen "lunged" at her in their living room, he said, she reasonably believed she was in danger.

"The state cannot prove beyond a reasonable doubt that was not the case," he said. "They cannot prove beyond a reasonable doubt that Ms. Ruth was not justified."

In the state's opening statement, Assistant Attorney General Andrew Prosser said the dispute leading up to the shooting was "started by, escalated by, and finished by Marique Ruth" and that Killen, whose name was on the lease for their home, had been justified in refusing to leave the house when Ruth and her adult son demanded he do so.

"She wasn’t in reasonable fear of anything," he said. "What she was in was anger with him for refusing to obey her instruction at gunpoint to leave his house."

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Jurors saw video walkthrough of shooting

On Wednesday, the jurors heard testimony from the lead detective on the case and watched videos of several interviews, including one at Ruth's home where she walked officers through her version of what had happened.

As Ruth told the officers, Killen had come back from hanging out with a friend, intoxicated and argumentative, and engaged in shouting matches with both her and her son. Both told him he should leave, and he refused.

Ruth, who had gotten her gun, said she picked it up to show she was "serious," and that Killen had tried to grab her over the back of their couch. She fired one shot meant as a warning, she said — although investigators believe it struck Killen in the arm — and then fired again as he continued to move. Ruth believed Killen was coming around the couch to attack her, although Prosser pointed out that Killen would have needed to walk in that direction to leave the house, as she requested.

Ruth, though, told detectives she was confident Killen had been coming for her.

"I was afraid for my life," she said. "I had already threatened to kill me once, he’d already threatened other women, I just wanted him to leave me alone."

William Morris covers courts for the Des Moines Register. He can be contacted at wrmorris2@registermedia.com or 715-573-8166.

This article originally appeared on Des Moines Register: Altoona woman's domestic violence murder trial ends in mistrial