Dateline: A Killing In Cottonwood - 5 harrowing details about Karen Duenas' murder, explored

The Dateline episode titled A Killing in Cottonwood aired on January 3, 2014, and followed the case of Karen Duenas, a 51-year-old woman who was murdered at her home in Cottonwood. The unfortunate incident occurred on the night of May 4, 2012. The next morning, Karen’s husband Mark discovered her blood-covered body.

While the Duenas family appeared to be just another normal couple with 5 sons, this murder and the subsequent investigation changed everything. Initially, the police had struggled to find a killer, and even serial killer theories were thought of but in a shocking turn of events, it was Mark who was later convicted of the murder.

Let us now explore the murder of Karen Duenas in detail including how it occurred and what led the police to arrest Mark.

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Karen Duenas was murdered in her home as shown in Dateline

The night of May 4, 2012, was initially just like any other night for the Duenas family. Karen and Mark had gone to their separate bedrooms to sleep. The couple had followed this sleeping arrangement for years given Mark’s erratic work schedules.

According to Mark, he had woken up the following morning with sounds that seemed like fighting cats. As he looked for the source of the sound and could not find anything, he decided to check on Karen and that is when he discovered his dead wife.

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Karen Duenas was stabbed to death

As revealed in Dateline, Karen was brutally stabbed three times, which resulted in her death. She was stabbed once in her chest and twice on her back and bled to death. When the police arrived after the 911 call that Mark made, they found her covered in blood and propped up on pillows.

What appeared a little strange was that while Karen’s body was lying in blood and there was a blood-covered blanket at her feet, her face and hands did not have any trace of blood. For a victim of stabbing, this was a strange and important detail.

Also Read: Dateline: The Devil Wore White - 5 harrowing details about Sante and Kenny Kimes' notorious crimes, explored

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It took the police 5 months to arrest Mark

After the investigation began, things seemed to be moving rather slowly as for the first few days there was no update on the case. This got the public worried and people demanded to know if they should be scared or if a serial killer was roaming around.

However, the sheriff’s department put those speculations at rest, saying,

"I urge the public to have trust in the Sheriff's Office. I mean I have family and friends that live in this neighborhood as well and based upon our original statement the public in general is not at risk. Our office still stands by that."

After 11 days of the murder, Mark was named as a potential suspect and even after that, no arrests were made. As things kept moving at their own pace, it was after 5 months that Mark got arrested as the key suspect in the Karen Duenas murder case.

Also Read: Dateline: The Feud - 5 harrowing details about Tim Newman's murder, explored

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Mark had an affair with another woman

Investigations led to Mark revealing his affair with Annette Green, a woman from Shasta County with whom Mark had gone to high school.

After several years of being out of touch, they reconnected via a Facebook mutual friend and started talking.

Eventually, Karen came to know of the relationship and naturally asked Mark to stop it. Mark, however, refused to do so and continued talking to Green on a track phone. Green also told the investigators that Mark had told her,

"Something bad would have to happen for us to be together."

This made Mark’s involvement in the murder more prominent.

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Mark had staged a break-in on the night of Karen’s killing

The Dateline episode showed the investigators reveal that Mark had tried to stage a robbery at their house on the night of Karen’s murder but made rookie mistakes.

The first point of discrepancy was that the room showed no sign of anyone else being there and the window, which could have served as an exit, was blocked by furniture.

Moreover, despite being a robbery attempt, nothing had been stolen from the family. Everything was left untouched in Karen’s room, which naturally hints that there was no robbery attempt at all.

Investigators also received that after making that 911 call, Mark acted rather strangely when the team arrived at the house. He kept lying down with a blanket on his face and at times asked if the police had found anything outside.

All these clues together helped the police to nab Mark. He was given a 25-year life sentence for his crimes.

Dateline can be streamed on NBC.

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