03/23/2012 03:09 pm ET Updated Mar 26, 2012

Martin 'David' Pietz Charged With Killing Wife Six Years After Her Death

Authorities in Washington state say they have cracked a cold case from six years ago, charging a husband with killing his wife.

Detectives with the King County Sheriff's Office Major Crimes Unit arrested 34-year-old Martin "David" Pietz Wednesday. The Lynnwood man is charged with second-degree murder in the death of his wife, 32-year-old Nicole Theresa Pietz.

"It took six years and 54 days, but we're finally there. We finally have an arrest," the victim's mother, Gael Schneider, told The Huffington Post.

Nicole Pietz was reported missing by her husband of four years to the Snohomish County Sheriff's Office on Jan. 28, 2006, after she failed to show up to a dinner party. A hiker stumbled upon her body nine days later in a wooded area outside of Lynnwood. An autopsy revealed that Pietz had been beaten and strangled.

From the onset of the investigation, police focused their attention on David Pietz. He gave misleading statements to investigators and failed a polygraph examination, police said.

Schneider, too, said she and her husband were convinced from the start that their son-in-law was responsible.

"It couldn't have been anybody but him. It could not have," she said.

NICOLE PIETZ CASE PHOTOS: (Article Continues Below)

Nicole Pietz Murder Case

According to a statement of probable cause, David Pietz told police he came home late from work on Jan. 27, 2006, and his wife was asleep when he got into bed. He said when he woke up around 8:20 a.m. the following morning, his wife had already left. Recent advances in forensic science, however, allegedly indicate Pietz is lying about the timeline of events in the case.

Investigators know Nicole Pietz purchased a taco dinner around 6 p.m. on Jan. 27. An examination of her stomach contents show the food was undigested. According to forensic examiners, the lack of digestion indicates Pietz was murdered within six hours of eating the meal.

Investigators also noted that Nicole Pietz was wearing a dental retainer when her body was found. According to the affidavit, she only wore the device at night, while sleeping.

Nicole Pietz’s vehicle, a 2003 Volkswagen Jetta, was found approximately two weeks after the discovery of her body, in a parking lot near the University of Washington.

In court documents filed Wednesday, prosecutors state David Pietz's DNA was found in several places in the vehicle that the car's last driver would have touched. His DNA was allegedly on the steering wheel, gear shift knob and windshield wiper knob.

Nicole Pietz's DNA was found in "very small quantities while the defendant's DNA was in much greater quantities," the court papers said. They also state that there was "no unidentified DNA in the car."

"It was new technology that allowed them to prove he was the last driver of her car," Schneider said.

In regard to a possible motive for the murder, prosecutors allege David Pietz was having extramarital affairs. Their marriage was "in some degree of turmoil," according to court documents.

"She had told somebody at work that morning that she had found out he was having yet another affair and I think that’s what happened -- she told him she wanted out or something," Schneider said.

She added, "It's so frustrating because I don't understand why he didn't just get out of [the marriage]."

David Pietz is being held on $1 million bail in the King County jail. His arraignment is scheduled for April 4.

Schneider said that while she is happy with the latest developments in the case, she does not expect the outcome to heal all of the pain she has carried the last six years.

"The wheels have been set in motion, but nothing's going to bring her back," Schneider said. "If we win the case -- if we get a conviction and he's behind bars for the rest of his life -- maybe then I'll be able to not think about it so much, but when your daughter's been beaten and strangled, how can you not think about it? Your children are your heart, and mine's broken."